Infusion pumps

ABSTRACT

Ambulatory infusion pumps, pump assemblies, cartridges, baseplates, cannulas, insertion tools, and related components as well as combinations thereof and related methods.

BACKGROUND

1. Field

The present devices and methods relate generally to ambulatory infusionpumps.

2. Description of the Related Art

Ambulatory infusion pumps (also referred to herein simply as “infusionpumps”) are relatively small, at least substantially self-containeddevices that are used to introduce drugs and other infusible substances(collectively “medicament”) into patients' bodies. Some infusion pumpsare configured to be worn on a belt or carried in a clothing pocket.Other infusion pumps are configured to be adhered to skin in patch-likefashion. Infusion pumps are advantageous in that they may be used to,for example, subcutaneously introduce (or “infuse”) medicament on anongoing or even continuous basis outside of a clinical environment.Infusion pumps are also advantageous in that they greatly reduce thefrequency of subcutaneous access events such as needle-based shots. Oneexample of a medicament that may be introduced by an infusion pump is aliquid formulation of insulin, which is a relatively large proteinmolecule used to treat diabetes mellitus. Other exemplary medicamentsthat may be introduced by an infusion pump include, but are not limitedto, drugs that treat cancers and drugs that suppress the perception ofpain.

Many conventional infusion pumps have improved patient health andquality of life. Nevertheless, the present inventors have determinedthat conventional infusion pumps are susceptible to a wide range ofimprovements. By way of example, but not limitation, the presentinventors have determined that it would be desirable to provide aninfusion pump that is smaller, more accurate and/or provides moreoperational flexibility than conventional infusion pumps.

SUMMARY

A medicament cartridge in accordance with at least one of the presentinventions includes a medicament reservoir, that has a total filledvolume, and a plunger movable to controllably dispense out of thereservoir an amount of medicament of 0.1% or less of the total filledvolume and with a single-dose precision of better than plus or minus20%. The reservoir may be defined by a cartridge barrel, and/or theprecision may be obtained within a dispensing period of less than eighthours. The present inventions also include apparatus that comprise sucha cartridge in combination with a pump assembly configured to drivefluid from the cartridge, such a cartridge in combination with abaseplate that can be attached to a pump assembly, and such a cartridgein combination with a cannula that may be in fluid communication withthe reservoir, as such pump assemblies, baseplates and cannulas aredescribed in the context of the examples herein, defined by the claimsherein or known to those of skill in the art, as well as systems thatcomprise such a cartridge in combination with two or more of a pumpassembly, a baseplate and a cannula.

A method in accordance with at least one of the present inventionsincludes pushing a plunger so as to controllably dispense out of amedicament reservoir an amount of medicament of 0.1% or less of thetotal filled volume of the reservoir and with a single-dose precision ofbetter than plus or minus 20%. The precision may be obtained within adispensing period of less than eight hours.

A medicament cartridge in accordance with at least one of the presentinventions includes a barrel and a plunger. The barrel defines at leasta substantial portion of a medicament reservoir having an inner surfaceand an outlet port. The plunger may be located within the barrel,include a plunger body having an outer surface with a pair of outerplunger-body rings that have tight tolerances with the inner surface ofthe barrel, a circumferential recessed area between plunger-body rings,and an o-ring structure, in the circumferential recessed area andcompressed by an inner surface of the barrel, having a pair of spacedcircumferential compressible rings. The present inventions also includeapparatus that comprise such a cartridge in combination with a pumpassembly configured to drive fluid from the cartridge, such a cartridgein combination with a baseplate that can be attached to a pump assembly,and such a cartridge in combination with a cannula that may be in fluidcommunication with the reservoir, as such pump assemblies, baseplatesand cannulas are described in the context of the examples herein,defined by the claims herein or known to those of skill in the art, aswell as systems that comprise such a cartridge in combination with twoor more of a pump assembly, a baseplate and a cannula.

A medicament cartridge in accordance with at least one of the presentinventions includes a barrel defining an inner diameter and a plungermovable over a stroke length. The stroke length to inner diameter ratiomay be about 1.0 or less. The present inventions also include apparatusthat comprise such a cartridge in combination with a pump assemblyconfigured to drive fluid from the cartridge, such a cartridge incombination with a baseplate that can be attached to a pump assembly,and such a cartridge in combination with a cannula that may be in fluidcommunication with the reservoir, as such pump assemblies, baseplatesand cannulas are described in the context of the examples herein,defined by the claims herein or known to those of skill in the art, aswell as systems that comprise such a cartridge in combination with twoor more of a pump assembly, a baseplate and a cannula.

A medicament cartridge in accordance with at least one of the presentinventions includes a cartridge body defining a medicament reservoir andhaving an outlet port, a manifold, connected to the cartridge body,having a through-bore in fluid communication with the outlet port. Thepresent inventions also include apparatus that comprise such a cartridgein combination with a pump assembly configured to drive fluid from thecartridge, such a cartridge in combination with a baseplate that can beattached to a pump assembly, and such a cartridge in combination with acannula that may be in fluid communication with the reservoir, as suchpump assemblies, baseplates and cannulas are described in the context ofthe examples herein, defined by the claims herein or known to those ofskill in the art, as well as systems that comprise such a cartridge incombination with two or more of a pump assembly, a baseplate and acannula.

A system in accordance with at least one of the present inventionsincludes an infusion pump assembly, a medicament cartridge and abaseplate. The infusion pump assembly may include a housing, a cartridgereceiving area in the housing, and a plunger pusher. The medicamentcartridge may include a plunger, a through-bore and a medicamentreservoir having an outlet port. The baseplate may be configured to beattached to the housing. The infusion pump assembly and the medicamentcartridge may be respectively configured such that plunger will beoperably aligned with the plunger pusher when the medicament cartridgeis positioned in the cartridge receiving area and the baseplate isattached to the housing. The present inventions also include the pumpassembly, medicament cartridge and baseplate in the system on anindividual basis, as well as any and all pairings thereof.

An infusion pump system in accordance with at least one of the presentinventions includes a disposable first portion and a reusable secondportion. The disposable first portion includes a medicament reservoir,medicament in the reservoir, and the entire medicament fluid path of theinfusion pump system. The reusable second portion includes a motor andis free of any portion of the medicament fluid path. The disposablefirst portion and the reusable second portion may be respectivelyconfigured such that the reusable second portion is positionable in anoperative position where operation of the motor causes the medicament tobe dispensed out of the medicament reservoir. The present inventionsalso include the disposable and reusable portions of the system on anindividual basis.

An apparatus in accordance with at least one of the present inventionsincludes a medicament cartridge with a barrel having a reservoir and aplunger, and an infusion pump assembly including a housing with acartridge receiving area, a plunger pusher and a drive mechanism todrive the plunger pusher. The pusher may be unconnectable to the plungerand incapable of applying a pulling force to the plunger. The presentinventions also include the pump assembly and medicament cartridge inthe apparatus on an individual basis. The present inventions alsoinclude systems that comprise such an apparatus in combination with abaseplate and/or a cannula, as such baseplates and cannulas aredescribed in the context of the examples herein, defined by the claimsherein or known to those of skill in the art.

A medicament cartridge in accordance with at least one of the presentinventions includes a barrel defining a reservoir and a plunger, locatedin the barrel, that does not include structure which would allow a pumpassembly plunger pusher to pull the plunger. The present inventions alsoinclude apparatus that comprise such a cartridge in combination with apump assembly configured to drive fluid from the cartridge, such acartridge in combination with a baseplate that can be attached to a pumpassembly, and such a cartridge in combination with a cannula that may bein fluid communication with the reservoir, as such pump assemblies,baseplates and cannulas are described in the context of the examplesherein, defined by the claims herein or known to those of skill in theart, as well as systems that comprise such a cartridge in combinationwith two or more of a pump assembly, a baseplate and a cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing including a medicament cartridge storagearea, a first face having a medicament cartridge insertion opening, asecond face opposite the first face and having a cartridge observationopening, a fluid displacement device associated with the cartridgestorage area, and a drive mechanism that drives the fluid displacementdevice. The present inventions also include apparatus that comprise sucha pump assembly in combination with a medicament cartridge, such a pumpassembly in combination with a baseplate that can be attached thereto,and such a pump assembly in combination with a cannula, as suchcartridges, baseplates and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art, as well as systems that comprise such a pump assembly incombination with two or more of a medicament cartridge, a baseplate anda cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a pump housing having opposing first and secondfaces, a plunger pusher and a drive mechanism that moves the plungerpusher bi-directionally along an axis. The first face may have aninsertion opening generally normal to the axis through which themedicament cartridge can be inserted into an inserted position. Thepresent inventions also include apparatus that comprise such a pumpassembly in combination with a medicament cartridge, such a pumpassembly in combination with a baseplate that can be attached thereto,and such a pump assembly in combination with a cannula, as suchcartridges, baseplates and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art, as well as systems that comprise such a pump assembly incombination with two or more of a medicament cartridge, a baseplate anda cannula.

An apparatus in accordance with at least one of the present inventionsincludes an infusion pump assembly and a baseplate. The infusion pumpassembly may include a housing having opposing first and second faces, aplunger pusher, and a drive mechanism that moves the plunger pusheralong an axis. The first face may have a medicament cartridge insertionopening through which the medicament cartridge can be inserted to aninserted position in the housing and operatively aligned with theplunger pusher. The baseplate may be attachable to the housing so as toat least partially cover the insertion opening with a cartridge in theinserted position. The present inventions also include the pump assemblyand baseplate in the apparatus on an individual basis. The presentinventions also include systems that comprise such an apparatus incombination with a medicament cartridge and/or a cannula, as suchcartridges and cannulas are described in the context of the examplesherein, defined by the claims herein or known to those of skill in theart.

A method in accordance with at least one of the present inventionsincludes the step of inserting a medicament cartridge, which has amedicament reservoir and a plunger, through a pump assembly housinginsertion opening in a direction generally perpendicular to the driveaxis of the pump assembly plunger pusher to an inserted position wherethe plunger is operatively aligned with the plunger pusher.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing having a medicament cartridge insertionopening, a chassis defining a medicament cartridge compartmentcommunicating with the insertion opening, and a plunger pusher movablein and out of the medicament cartridge compartment. The insertionopening may be generally normal to a longitudinal axis of the plungerpusher. The present inventions also include apparatus that comprise sucha pump assembly in combination with a medicament cartridge having aplunger, such a pump assembly in combination with a baseplate that canbe attached thereto, and such a pump assembly in combination with acannula, as such cartridges, baseplates and cannulas are described inthe context of the examples herein, defined by the claims herein orknown to those of skill in the art, as well as systems that comprisesuch a pump assembly in combination with two or more of a medicamentcartridge, a baseplate and a cannula.

An infusion pump apparatus in accordance with at least one of thepresent inventions includes an infusion pump assembly, with a housingand a plunger pusher, and a medicament cartridge. The medicamentcartridge may be positionable in the housing in an inserted position andhave a cartridge front wall with an outer surface, a medicamentreservoir, and a plunger having a dry side. The infusion pump assemblymay also have a clamp that clamps the reservoir between the dry side ofthe plunger and the outer surface of the cartridge front wall. Thepresent inventions also include the pump assembly and medicamentcartridge in the apparatus on an individual basis. The presentinventions also include systems that comprise such an apparatus incombination with a baseplate and/or a cannula, as such baseplates andcannulas are described in the context of the examples herein, defined bythe claims herein or known to those of skill in the art.

An infusion pump apparatus in accordance with at least one of thepresent inventions includes an infusion pump assembly, with a housing,and a medicament cartridge. The pump assembly housing may have acartridge receiving area defining a forward corner. The medicamentcartridge may have a reservoir and an unpowered part of an occlusionsensor. A powered part of the occlusion sensor may be positioned in thepump assembly housing, outside of the medicament cartridge and proximateto the forward corner of the cartridge receiving area. The infusion pumpassembly may also include at least one resilient member positioned tobias the medicament cartridge when in the inserted position into theforward corner of the receiving area. The present inventions alsoinclude the pump assembly and medicament cartridge in the apparatus onan individual basis. The present inventions also include systems thatcomprise such an apparatus in combination with a baseplate and/or acannula, as such baseplates and cannulas are described in the context ofthe examples herein, defined by the claims herein or known to those ofskill in the art.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing having therein a plunger pusher and achassis. The chassis defines a forward area and a rear end, and mayinclude first and second side frame members, attached together andforming a cartridge receiving compartment at the forward area of thechassis, and a gear cap attached with at least one fastener to at leastone of the first and second side frame members at the rear end of thechassis. The present inventions also include apparatus that comprisesuch a pump assembly in combination with a medicament cartridge, such apump assembly in combination with a baseplate that can be attachedthereto, and such a pump assembly in combination with a cannula, as suchcartridges, baseplates and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art, as well as systems that comprise such a pump assembly incombination with two or more of a medicament cartridge, a baseplate anda cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing with a cartridge insertion opening and acartridge receiving area communicating with the insertion opening, arigid wall securely mounted in the cartridge receiving area, a devicethat engages an aft end of a medicament cartridge and pushes themedicament cartridge against the rigid wall to a held position. Aplunger pusher and a plunger pusher drive mechanism may be provided inthe housing. The present inventions also include apparatus that comprisesuch a pump assembly in combination with a medicament cartridge, such apump assembly in combination with a baseplate that can be attachedthereto, and such a pump assembly in combination with a cannula, as suchcartridges, baseplates and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art, as well as systems that comprise such a pump assembly incombination with two or more of a medicament cartridge, a baseplate anda cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing having a cartridge receiving area, aplunger pusher and a pusher drive mechanism, and a contact member biasedforward so that an end thereof extends into the cartridge receivingarea. The contact member, with a cartridge in the cartridge receivingarea and the plunger pusher in a non-retracted position, may be blockedfrom rearward movement relative to the cartridge receiving area andthereby locking the cartridge in the cartridge receiving area. Thecontact member, with the plunger pusher in a retracted position, may beable to retract relative to the receiving area thereby allowing thecartridge to be inserted into or removed from the inserted position. Thepresent inventions also include apparatus that comprise such a pumpassembly in combination with a medicament cartridge, such a pumpassembly in combination with a baseplate that can be attached thereto,and such a pump assembly in combination with a cannula, as suchcartridges, baseplates and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art, as well as systems that comprise such a pump assembly incombination with two or more of a medicament cartridge, a baseplate anda cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing and an interlock. The housing may have acartridge receiving area, a plunger pusher and a plunger drivemechanism. The interlock prevents removal of a medicament cartridge fromthe cartridge receiving area when the cartridge is in the insertedposition and the plunger pusher is in a non-retracted position, andallows removal of the medicament cartridge from the cartridge receivingarea when the cartridge is in the inserted position and the plungerpusher is a retracted position. The present inventions also includeapparatus that comprise such a pump assembly in combination with amedicament cartridge, such a pump assembly in combination with abaseplate that can be attached thereto, and such a pump assembly incombination with a cannula, as such cartridges, baseplates and cannulasare described in the context of the examples herein, defined by theclaims herein or known to those of skill in the art, as well as systemsthat comprise such a pump assembly in combination with two or more of amedicament cartridge, a baseplate and a cannula.

A method of operating a pump module in accordance with at least one ofthe present inventions includes the step of causing a cartridge biasingmember to change from a blocking condition where the member blocksremoval of a medicament cartridge from the pump module, to a releasecondition where the cartridge biasing member allows the medicamentcartridge to be removed from the pump module, in response to a receiptof an instruction from a remote control.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing with a medicament cartridge receivingarea, a plunger pusher located in the housing and movable in and out ofthe cartridge receiving area, and a slidable latch movable between afirst position that does not prevent a medicament cartridge from beinginserted into and removed from the cartridge receiving area and a secondposition, when at least a portion of the pusher is in the cartridgereceiving area, that prevents removal of the medicament cartridge fromthe cartridge receiving area. The present inventions also includeapparatus that comprise such a pump assembly in combination with amedicament cartridge, such a pump assembly in combination with abaseplate that can be attached thereto, and such a pump assembly incombination with a cannula, as such cartridges, baseplates and cannulasare described in the context of the examples herein, defined by theclaims herein or known to those of skill in the art, as well as systemsthat comprise such a pump assembly in combination with two or more of amedicament cartridge, a baseplate and a cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing with a medicament cartridge receivingarea, a plunger pusher located in the housing and movable between a homeposition outside the cartridge receiving area and a position within thecartridge receiving area, a drive mechanism, including a motor,operatively connected to the plunger pusher, and a switch. The switchmay be located relative to the plunger pusher such that the switch isactuated when the plunger pusher is retracted, from a position where atleast a portion of the plunger pusher is within the cartridge receivingarea, to a home position. The present inventions also include apparatusthat comprise such a pump assembly in combination with a medicamentcartridge, such a pump assembly in combination with a baseplate that canbe attached thereto, and such a pump assembly in combination with acannula, as such cartridges, baseplates and cannulas are described inthe context of the examples herein, defined by the claims herein orknown to those of skill in the art, as well as systems that comprisesuch a pump assembly in combination with two or more of a medicamentcartridge, a baseplate and a cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing having a cartridge receiving area, aplunger pusher movable in and out of the cartridge receiving area, apusher drive mechanism including a motor and a controller. Thecontroller may be configured to automatically cause the motor towithdraw the plunger pusher out of the cartridge receiving area (a)after receiving a signal from the encoder indicating that apredetermined number of rotation counts of the motor, which indicatethat the reservoir is empty, have occurred or (b) when there is a lackof encoder signals. The present inventions also include apparatus thatcomprise such a pump assembly in combination with a medicamentcartridge, such a pump assembly in combination with a baseplate that canbe attached thereto, and such a pump assembly in combination with acannula, as such cartridges, baseplates and cannulas are described inthe context of the examples herein, defined by the claims herein orknown to those of skill in the art, as well as systems that comprisesuch a pump assembly in combination with two or more of a medicamentcartridge, a baseplate and a cannula.

An apparatus in accordance with at least one of the present inventionsincludes a medicament cartridge and an infusion pump assembly. Themedicament cartridge may have a reservoir and a plunger. The infusionpump assembly may include a housing having a cartridge receivingcompartment and a plunger pusher defining a longitudinal axis. Theplunger pusher may be movable from a home position allowing themedicament cartridge to be inserted into and removed from the cartridgereceiving compartment in a direction generally perpendicular to thelongitudinal axis of the plunger pusher and another position wherein atleast a portion of the plunger pusher is in the medicament cartridge.The present inventions also include the pump assembly and medicamentcartridge in the apparatus on an individual basis. The presentinventions also include systems that comprise such an apparatus incombination with a baseplate and/or a cannula, as such baseplates andcannulas are described in the context of the examples herein, defined bythe claims herein or known to those of skill in the art.

An apparatus in accordance with at least one of the present inventionsincludes an infusion pump assembly, a medicament cartridge and a latchassembly. The infusion pump assembly may include a housing and a plungerpusher that moves the plunger pusher along a pusher axis. The medicamentcartridge may include a barrel, defining a medicament reservoir, and aplunger in the barrel, and be positioned in the housing such that theplunger pusher is positioned to push the plunger. The latch assembly maybe configured to block removal of the medicament cartridge from thehousing in a direction orthogonal to the pusher axis when at least aportion of the pusher is within the cartridge. The present inventionsalso include the pump assembly, medicament cartridge and latch assemblyin the apparatus on an individual basis. The present inventions alsoinclude systems that comprise such an apparatus in combination with abaseplate and/or a cannula, as such baseplates and cannulas aredescribed in the context of the examples herein, defined by the claimsherein or known to those of skill in the art.

An apparatus in accordance with at least one of the present inventionsincludes an infusion pump assembly with a housing having a cartridgereceiving area, a baseplate that is attachable to the housing and has anopening and bottom surface adhesive, a movable member, and an alarm. Themovable member may be pushed to a first position by the user's skin whenthe baseplate is adhered to the user's skin by the adhesive and may bebiased to a second position extended out the opening in the baseplatewhen the baseplate is separated from the user's skin after attachmentthereto. The alarm may be activated in response to the movable membermoving to the second position. The present inventions also include thevarious components in the apparatus on an individual basis, as well asany and all combinations thereof. The present inventions also includesystems that comprise such an apparatus in combination with a medicamentcartridge and/or a cannula, as such cartridges and cannulas aredescribed in the context of the examples herein, defined by the claimsherein or known to those of skill in the art.

An apparatus in accordance with at least one of the present inventionsincludes an infusion pump assembly with a housing having a cartridgereceiving area, a controller, an alarm, a baseplate that is attachableto the housing and has bottom surface adhesive, and an RF circuit. TheRF circuit may include a transmitting antenna and a receiving antenna,and be configured to send a signal to the controller, indicating thatthe baseplate has become separated from the user's skin. The controllermay activate the alarm in response. The present inventions also includethe various components in the apparatus on an individual basis, as wellas any and all combinations thereof. The present inventions also includesystems that comprise such an apparatus in combination with a medicamentcartridge and/or a cannula, as such cartridges and cannulas aredescribed in the context of the examples herein, defined by the claimsherein or known to those of skill in the art.

An apparatus in accordance with at least one of the present inventionsincludes an infusion pump assembly with a housing having a cartridgereceiving area, a controller, an alarm, a baseplate that is attachableto the housing and has bottom surface adhesive, and an electricalcircuit. The electrical circuit may include a first terminal and asecond terminal spaced from the first terminal, be configured to becompleted between the first and second terminals by the user's skin whenthe baseplate is adhered to the skin by the adhesive, to be broken whenthe baseplate becomes separated from the user's skin, and to send asignal to the controller when the baseplate has become separated fromthe user's skin. The controller may activate the alarm in response. Thepresent inventions also include the various components in the apparatuson an individual basis, as well as any and all combinations thereof. Thepresent inventions also include systems that comprise such an apparatusin combination with a medicament cartridge and/or a cannula, as suchcartridges and cannulas are described in the context of the examplesherein, defined by the claims herein or known to those of skill in theart.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing having a cartridge compartment, a fluiddisplacement device, and a rechargeable battery, adapted to drive thefluid displacement device, mounted in the housing outside of thecartridge compartment. The present inventions also include apparatusthat comprise such a pump assembly in combination with a medicamentcartridge, such a pump assembly in combination with a baseplate that canbe attached thereto, and such a pump assembly in combination with acannula, as such cartridges, baseplates and cannulas are described inthe context of the examples herein, defined by the claims herein orknown to those of skill in the art, as well as systems that comprisesuch a pump assembly in combination with two or more of a medicamentcartridge, a baseplate and a cannula.

A method in accordance with at least one of the present inventions mayinclude the steps of removing, from an assembled device that includes aninfusion pump assembly with a medicament cartridge therein and abaseplate secured to the pump assembly housing, the pump assemblyhousing from the baseplate, connecting the recharging terminals on thepump assembly to a recharging device, and recharging the rechargeablebattery in the housing.

A system in accordance with at least one of the present inventionsincludes a baseplate, a cannula, a pump assembly, a battery rechargingunit, and a controller. The pump assembly may include a housing, amedicament reservoir, a fluid displacement device, and a rechargeablebattery for the fluid displacement device in the housing. The housingmay be separable from the baseplate and cannula with the cannularemaining secured to and extending out from the baseplate such that thehousing is in a separate condition. The housing, in the separatecondition, may be operatively connected to the battery recharging unitsuch that the recharging of the battery by the recharging unit iscontrolled by the controller. The present inventions also include thevarious components in the system on an individual basis, as well as anyand all combinations thereof.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing with a cartridge receiving area, a plungerpusher, a stepper motor, having a shaft and coils, operatively connectedto the plunger pusher, an encoder, operably connected to the motorshaft, that generates encoder output representative of shaft position, abattery operatively connected to the motor, an analog-to-digital (A/D)converter that generates A/D converter output that is a digitalrepresentation of battery voltage, and a controller. The controller may(a) operate through a driver circuit to control the operation of themotor and to pulse-width modulate energy from the battery applied to themotor coils, (b) read the encoder output and (c) read the A/D converteroutput. The present inventions also include apparatus that comprise sucha pump assembly in combination with a medicament cartridge, such a pumpassembly in combination with a baseplate that can be attached thereto,and such a pump assembly in combination with a cannula, as suchcartridges, baseplates and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art, as well as systems that comprise such a pump assembly incombination with two or more of a medicament cartridge, a baseplate anda cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing, having a medicament cartridge receivingarea, a fluid displacement device, a drive mechanism that drives thefluid displacement device, a receiving area sensor that senses when thecartridge sensor element is in a predetermined location within thecartridge receiving area, and a controller operably connected to thesensor and drive mechanism. The controller may be configured to preventthe drive mechanism from driving the fluid displacement device unlessthe receiving area sensor senses that the cartridge sensor element is inthe predetermined location. The present inventions also includeapparatus that comprise such a pump assembly in combination with amedicament cartridge, such a pump assembly in combination with abaseplate that can be attached thereto, and such a pump assembly incombination with a cannula, as such cartridges, baseplates and cannulasare described in the context of the examples herein, defined by theclaims herein or known to those of skill in the art, as well as systemsthat comprise such a pump assembly in combination with two or more of amedicament cartridge, a baseplate and a cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing, a plunger pusher, a medicament reservoir,a plunger, a drive mechanism that drives the plunger pusher and has astepper motor and an encoder, and a controller. The controller may beconfigured to cause the motor to propel the pusher against the plungeraccording to a medicament dispensing program having a plurality ofdispensing operations and to, for at least one of the dispensingoperations, cause the motor to stop from a pusher propelling velocity byslowly decreasing the frequency of the waveform delivered to the motorto maintain constant positive control of the motor and thereby toprecisely control how many turns the motor makes and thus the precisedistance the pusher advances before stopping. Such precise distancecontrol results in accurate controlled medicament dispensing from thereservoir. The present inventions also include systems that comprisesuch an apparatus in combination with a baseplate and/or a cannula, assuch baseplates and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art.

A method in accordance with at least one of the present inventionsincludes the steps of propelling a plunger pusher relative to theplunger of a medicament cartridge with a motor, and controlling motortorque such that the torque is continuously within a range having alower limit that is sufficient to overcome stiction of the cartridgeplunger and move the plunger and an upper limit that is low enough so asto not cause leakage past plunger seals due to excessive pressure in thecartridge reservoir.

A system in accordance with at least one of the present inventionsincludes a medicament cartridge, an infusion pump assembly, a baseplate,and a cannula. The medicament cartridge may have a medicament reservoirand a manifold connected to the medicament reservoir and having athrough-bore. The infusion pump assembly may be configured to receivethe medicament cartridge. The baseplate may have a baseplate opening andbottom surface adhesive, and be configured to be secured to the infusionpump assembly. The cannula may be dimensioned to be inserted through thethrough-bore and the baseplate opening, when the medicament cartridge inplace in the infusion pump assembly and the baseplate attached to theinfusion pump assembly, to an inserted position. The baseplate and thecannula may be respectively configured such that the baseplate and thecannula will be secured to one another when the cannula reaches theinserted position and will remain secured to one another when theinfusion pump assembly is subsequently removed from the baseplate. Thepresent inventions also include the pump assembly, medicament cartridge,baseplate and cannula in the system on an individual basis, as well asany and all pairings thereof.

A system in accordance with at least one of the present inventionsincludes a medicament cartridge having a reservoir and a manifoldthrough-bore, a pump assembly including a medicament cartridge receivingarea, a bottom surface, and a bottom surface opening, and a baseplate,having a baseplate opening, configured to be secured to the pumpassembly. The medicament cartridge, pump assembly and baseplate may berespectively configured such that when the baseplate is secured to thepump assembly with the medicament cartridge in the cartridge receivingarea, the baseplate will be over the bottom surface opening and thebaseplate opening will be aligned with the manifold through-bore. Thecannula may be dimensioned to be inserted into the manifold through-boreand the baseplate opening. The present inventions also include the pumpassembly, medicament cartridge, baseplate and cannula in the system onan individual basis, as well as any and all pairings thereof.

An infusion pump cannula in accordance with at least one of the presentinventions includes a cannula head having a bottom opening, a sideopening, a medicament fluid path between the side and bottom openings,an upper sealing device above the side opening and a lower sealingdevice below the side opening, and a cannula tube connected to thecannula head and in fluid communication with the medicament fluid path.The cannula head and/or the cannula may be configured to secure theinfusion pump cannula to the opening in an infusion pump baseplate. Thepresent inventions also include apparatus that comprise such a cannulain combination with a pump assembly configured to drive fluid from acartridge, such a cannula in combination with a baseplate that can beattached to a pump assembly, and such a cannula in combination with acartridge, as such pump assemblies, baseplates and cartridges aredescribed in the context of the examples herein, defined by the claimsherein or known to those of skill in the art, as well as systems thatcomprise such a cannula in combination with two or more of a pumpassembly, a baseplate and a cartridge.

An apparatus in accordance with at least one of the present inventionsincludes an infusion pump assembly and a baseplate. The infusion pumpassembly may include a housing having a cartridge receiving area, abottom opening, and housing electrical contacts. The infusion pumpassembly may also include a fluid displacement device, a drive mechanismthat drives the fluid displacement device, and a slidable latchassociated with the housing. The slidable latch may be movable between aunlatched position that does not prevent the medicament cartridge frombeing inserted into and removed from the cartridge receiving area and alatched position that prevents removal of the medicament cartridge fromthe cartridge receiving area, and have a protruding portion. Thebaseplate may be configured to at least partially cover the housingbottom opening, and may have an upper surface, a recessed area on theupper surface, and baseplate electrical contacts. The infusion pumpassembly and baseplate may be respectively configured such that (1) thebaseplate and housing may be attachable to one another with thebaseplate electrical contacts in electrical contact with the housingelectrical contacts and (2) the baseplate and housing can only beattached to one another when the slidable latch is in the latchedposition and the protruding portion mates with the recessed area. Thepresent inventions also include the pump assembly and baseplate in theapparatus on an individual basis. The present inventions also includesystems that comprise such an apparatus in combination with a medicamentcartridge and/or a cannula, as such cartridges and cannulas aredescribed in the context of the examples herein, defined by the claimsherein or known to those of skill in the art.

An apparatus in accordance with at least one of the present inventionsincludes an infusion pump assembly and a baseplate. The infusion pumpassembly may include a housing having a medicament cartridge receivingarea, a fluid displacement device in the housing, and a drive mechanismoperably connected to the fluid displacement device. The baseplate maybe attachable to the housing, define a bottom surface and a cannulaopening, and include a first adhesive on the bottom surface adjacent toan opening for a cannula and a second adhesive on the bottom surface andspaced a distance away from the opening, the first adhesive being anadhesive that adheres more aggressively to human skin than the secondadhesive. The present inventions also include the pump assembly andbaseplate in the apparatus on an individual basis. The presentinventions also include systems that comprise such an apparatus incombination with a medicament cartridge and/or a cannula, as suchcartridges and cannulas are described in the context of the examplesherein, defined by the claims herein or known to those of skill in theart.

An apparatus in accordance with at least one of the present inventionsincludes an infusion pump assembly and a baseplate. The infusion pumpassembly may include a housing, having a cartridge receiving area, afluid displacement device, and a fluid displacement device drivemechanism. The baseplate may include a plate member having a topopening, an edge opening and a baseplate fluid path between the topopening and the edge opening, a tubing at the edge opening andcommunicating with an end of the fluid path, and a connector having anopening in the cartridge receiving area that defines at least a portionof a fluid path between the cartridge receiving area and the baseplatefluid path. The present inventions also include the pump assembly andbaseplate in the apparatus on an individual basis. The presentinventions also include systems that comprise such an apparatus incombination with a medicament cartridge and/or a cannula, as suchcartridges and cannulas are described in the context of the examplesherein, defined by the claims herein or known to those of skill in theart.

A method in accordance with at least one of the present inventionsincludes making a baseplate type determination with the controller basedon the baseplate identification device and controlling the fluiddisplacement device with the controller based at least in part on thedetermined baseplate type.

A system in accordance with at least one of the present inventionsincludes a housing, a fluid displacement device and drive mechanism inthe housing, a rechargeable battery in the housing and adapted to powerthe drive mechanism, a pair of contacts operatively connected to therechargeable battery and supported by the housing, and a controller. Thecontroller may determine from a detected resistor value whether the pairof contacts is operatively connected to terminals of a first baseplatehaving a first resistor value or to terminals of a second baseplatehaving a second resistor value. The controller may also operate thedrive mechanism in a first mode associated with the first baseplate inresponse to a first baseplate determination and operate the drivemechanism is a second mode associated with the second baseplate inresponse to a second baseplate determination. The present inventionsalso include systems that also include a medicament cartridge and/or acannula, as such cartridges and cannulas are described in the context ofthe examples herein, defined by the claims herein or known to those ofskill in the art.

A kit in accordance with at least one of the present inventions includesa first baseplate, a second baseplate, and an infusion pump assembly.The first baseplate may have a first baseplate pattern of targets, andthe second baseplate may have a second baseplate pattern of targets thatis different than the first pattern. The infusion pump assembly mayinclude an emitter/detector configured to detect the first and secondbaseplate patterns and a controller configured to determine, based on adetected baseplate pattern, which of the first and second baseplates isattached to the housing. The controller may also be configured tooperate in a first mode when the first baseplate is attached to thehousing, and to operate in a second mode, which is different than thefirst mode, when the second baseplate is attached to the housing. Thetargets may be, in some implementations, reflective and/or occludedtargets. The present inventions also include the pump assembly andbaseplate sets of the kit on an individual basis. The present inventionsalso include a kit that comprises a baseplate set and a medicamentcartridge. The present inventions also include systems that comprisesuch a kit in combination with a medicament cartridge and/or a cannula,as such cartridges and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art.

A kit in accordance with at least one of the present inventions includesa first baseplate, a second baseplate, and an infusion pump assembly.The first baseplate may have a first baseplate identification device,and the second baseplate may have a second baseplate identificationdevice. The infusion pump assembly may include a connector assembly thatoperatively connects to an identification device on a baseplate that issecured to the housing. The controller may be configured to determine,based on a detected baseplate identification device, which one of thefirst and second baseplates is attached to the housing. The presentinventions also include the pump assembly and baseplate sets of the kiton an individual basis. The present inventions also include a kit thatcomprises a baseplate set and a medicament cartridge. The presentinventions also include systems that comprise such a kit in combinationwith a medicament cartridge and/or a cannula, as such cartridges andcannulas are described in the context of the examples herein, defined bythe claims herein or known to those of skill in the art.

A system in accordance with at least one of the present inventionsincludes a medicament cartridge, an infusion pump assembly, a baseplate,and a cannula. The medicament cartridge, infusion pump assembly,baseplate and cannula may be respectively configured such that, when themedicament cartridge is in the pump assembly cartridge receiving areaand the baseplate is attached to the pump assembly housing, the cannulacan be inserted through a cartridge through-bore and a baseplate openingand connected to the baseplate, thereby defining abaseplate-cartridge-cannula unit. The medicament cartridge, infusionpump assembly, baseplate and cannula may also be configured such that,when the pump assembly pusher is in the home position and a latch is inthe non-blocking position, the infusion pump assembly is separable fromthe baseplate-cartridge-cannula unit. The present inventions alsoinclude the pump assembly, medicament cartridge and baseplate in thesystem on an individual basis, as well as any and all pairings thereof.

A method in accordance with at least one of the present inventionsincludes the step of arranging a medicament cartridge, infusion pumpassembly, baseplate and cannula into an assembled system where at leastthe medicament cartridge and the cannula define a medicament dispensingflow path unit, and removing the infusion pump assembly from themedicament dispensing flow path unit.

An apparatus in accordance with at least one of the present inventionsincludes a medicament cartridge and an infusion pump assembly. Themedicament cartridge may include a medicament reservoir, a plunger andan outlet port. The infusion pump assembly may include a housing havinga cartridge receiving area, a plunger pusher, a drive mechanism, thatdrives the plunger pusher and has a motor, a lead screw, a gear assemblyoperatively positioned between the motor and the lead screw, and anencoder, and a controller. The medicament cartridge may be insertablethrough an opening in the housing and into the cartridge receiving areato an inserted position where the plunger is proximate to but spacedfrom the plunger pusher. The controller may be configured to execute,with the medicament cartridge in the inserted position, a plunger pusherzeroing procedure including causing the motor to advance the plungerpusher to contact the plunger and then to back the plunger pusher off apredetermined distance from the plunger. The present inventions alsoinclude the pump assembly and medicament cartridge in the apparatus onan individual basis. The present inventions also include systems thatcomprise such an apparatus in combination with a baseplate and/or acannula, as such baseplates and cannulas are described in the context ofthe examples herein, defined by the claims herein or known to those ofskill in the art.

An apparatus in accordance with at least one of the present inventionsincludes a medicament cartridge and an infusion pump assembly. Themedicament cartridge may include a medicament reservoir, a plunger, anoutlet port, a removable seal positioned at the outlet port, Theinfusion pump assembly may include a housing with a cartridge receivingarea, a plunger pusher, and a drive mechanism. The medicament cartridgemay be inserted through an opening in the housing with the seal in asealed position and into the cartridge receiving area to an insertedposition where the plunger proximate to but spaced a small distance fromthe plunger pusher. The present inventions also include the pumpassembly and medicament cartridge in the apparatus on an individualbasis. The present inventions also include systems that comprise such anapparatus in combination with a baseplate and/or a cannula, as suchbaseplates and cannulas are described in the context of the examplesherein, defined by the claims herein or known to those of skill in theart.

An infusion pump method in accordance with at least one of the presentinventions, which may be associated with an infusion pump assemblyincluding a plunger pusher and a medicament cartridge including areservoir and a plunger that has a dry side and an outlet port, includesthe steps of propelling the plunger pusher such that the plunger pushercontacts the dry side of a plunger while the plunger outlet port issealed and, in response to sensing that the plunger pusher has contactedthe plunger, reversing the drive direction of the motor to withdraw theplunger pusher a predetermined distance from the dry side of the plungeras part of a plunger pusher zeroing procedure.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing, having a cartridge receiving area, aplunger pusher, a motor to drive the plunger pusher, an encoderassociated with the motor, and a controller. The controller may beconfigured to control the operation of the motor and to adjust amedicament dispensing program to compensate for the amount of reverserotation of the motor that occurs when electrical power is not beingdelivered to the motor and the controller receives a signal from theencoder that the controller interprets as a reverse motor rotationsignal. The present inventions also include apparatus that comprise sucha pump assembly in combination with a medicament cartridge, such a pumpassembly in combination with a baseplate that can be attached thereto,and such a pump assembly in combination with a cannula, as suchcartridges, baseplates and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art, as well as systems that comprise such a pump assembly incombination with two or more of a medicament cartridge, a baseplate anda cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing, a plunger pusher, a drive mechanism, witha motor and an encoder, to drive the plunger pusher, and a controller.The controller may store a medicament dispensing program and beconfigured to determine from signals from the encoder, when the motor isnot being electrically driven, whether the motor is rotating in reverseand to adjust the medicament dispensing program to take into account theamount of reverse rotation. The present inventions also includeapparatus that comprise such a pump assembly in combination with amedicament cartridge, such a pump assembly in combination with abaseplate that can be attached thereto, and such a pump assembly incombination with a cannula, as such cartridges, baseplates and cannulasare described in the context of the examples herein, defined by theclaims herein or known to those of skill in the art, as well as systemsthat comprise such a pump assembly in combination with two or more of amedicament cartridge, a baseplate and a cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing having a cartridge receiving area, aplunger pusher, a drive mechanism, with a motor and a gear assembly,that drives the plunger pusher, and a controller. The controller may beconfigured to detect operation errors of the motor and/or gear assemblyand/or to detect reverse turning of the motor when not receivingelectrical power. The present inventions also include apparatus thatcomprise such a pump assembly in combination with a medicamentcartridge, such a pump assembly in combination with a baseplate that canbe attached thereto, and such a pump assembly in combination with acannula, as such cartridges, baseplates and cannulas are described inthe context of the examples herein, defined by the claims herein orknown to those of skill in the art, as well as systems that comprisesuch a pump assembly in combination with two or more of a medicamentcartridge, a baseplate and a cannula.

A method in accordance with at least one of the present inventionsincludes the steps of dispensing medicament from an infusion pumpassembly reservoir in accordance with a medicament dispensing programand adjusting the medicament dispensing program to compensate for anamount of reverse rotation of the infusion pump assembly motor thatoccurs when electrical power is not being delivered to the motor.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing, having cartridge receiving area, aplunger pusher, a pusher drive mechanism with a motor, a lead screw, agear assembly operatively between the lead screw and the motor, and anencoder, and a controller operably connected to the motor. Thecontroller may be configured to (1) cause the motor to be powered at apredetermined dispensing torque level and (2) determine that the gearassembly is not operating properly, when the cartridge is not in thereceiving area, in response to receipt of at least one signal from theencoder indicating that the motor is turning when the motor is beingpowered to run at a low torque level that is below the predetermineddispensing torque level. The present inventions also include apparatusthat comprise such a pump assembly in combination with a medicamentcartridge, such a pump assembly in combination with a baseplate that canbe attached thereto, and such a pump assembly in combination with acannula, as such cartridges, baseplates and cannulas are described inthe context of the examples herein, defined by the claims herein orknown to those of skill in the art, as well as systems that comprisesuch a pump assembly in combination with two or more of a medicamentcartridge, a baseplate and a cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing, having a cartridge receiving area, aplunger pusher, a drive mechanism, including a motor, that drives theplunger pusher, and a controller that controls the operation of themotor. The controller may be configured to automatically withdraw thepusher to a home position in response to a receipt of a signalindicating that the medicament reservoir is empty. The presentinventions also include apparatus that comprise such a pump assembly incombination with a medicament cartridge, such a pump assembly incombination with a baseplate that can be attached thereto, and such apump assembly in combination with a cannula, as such cartridges,baseplates and cannulas are described in the context of the examplesherein, defined by the claims herein or known to those of skill in theart, as well as systems that comprise such a pump assembly incombination with two or more of a medicament cartridge, a baseplate anda cannula.

A method in accordance with at least one of the present inventionsincludes the steps of pushing the plunger of a medicament cartridgelocated in an infusion pump assembly with a plunger pusher such that aportion of the plunger pusher is within the medicament cartridge, andwithdrawing the plunger pusher from within the medicament cartridge,without instruction from the user to do so, in response to adetermination by the infusion pump assembly that the medicamentcartridge is empty.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing configured to receive a medicamentcartridge, a plunger pusher, a pusher drive mechanism with a motor, alead screw, a gear assembly, and an encoder, and a controller. Thecontroller may be configured to execute a gear assembly verificationprocedure including the following procedure parts: (a) delivering motordriving sequence of pulses to the motor instructing torque to be appliedin a rewind direction to the motor at less than 70% of a torque appliedfor normal delivery in a forward direction and thereby rotating themotor, (b) determining that the gear assembly is not operating properlyif signals from the encoder indicate that the motor is approximatelysynchronized with the motor driving sequence of pulses, and (c)determining that the gear assembly is operating properly if signals fromthe encoder indicate that the motor is not synchronized with the motordriving sequence of pulses. The present inventions also includeapparatus that comprise such a pump assembly in combination with amedicament cartridge, such a pump assembly in combination with abaseplate that can be attached thereto, and such a pump assembly incombination with a cannula, as such cartridges, baseplates and cannulasare described in the context of the examples herein, defined by theclaims herein or known to those of skill in the art, as well as systemsthat comprise such a pump assembly in combination with two or more of amedicament cartridge, a baseplate and a cannula.

An infusion pump assembly in accordance with at least one of the presentinventions includes a housing, a plunger pusher, a drive mechanism andalarm. The pump assembly may be configured such that the alarm will beactivated when one, all, or any combination of less than all of thefollowing conditions is met: (1) no baseplate is attached to thehousing, (2) a baseplate attached to the housing becomes separated fromthe skin of a user, (3) the plunger pusher does not contact the dry sideof a reservoir plunger after advancing a predetermined distance or arange of predetermined distances corresponding to an expected locationof the dry side of the plunger in a pusher zeroing procedure, (4) atemperature in the housing exceeds a predetermined temperature, (5)motor current is too low, and (6) the battery has a charging fault. Thepresent inventions also include apparatus that comprise such a pumpassembly in combination with a medicament cartridge, such a pumpassembly in combination with a baseplate that can be attached thereto,and such a pump assembly in combination with a cannula, as suchcartridges, baseplates and cannulas are described in the context of theexamples herein, defined by the claims herein or known to those of skillin the art, as well as systems that comprise such a pump assembly incombination with two or more of a medicament cartridge, a baseplate anda cannula.

An apparatus in accordance with at least one of the present inventionsincludes an infusion pump assembly and a remote control. The infusionpump assembly may include a controller that stores medicament dispensingprogram information, determines time remaining in the dispensing programbased at least in part on the medicament dispensing program informationand encoder signals, and generates a time remaining signal.Alternatively, or in addition, the controller may be configured todetermine the amount of time remaining until the pump assembly batterywill require recharging and generate a time remaining signal. The remotecontrol may include a user interface, be operably connected to the pumpassembly controller, and be configured to generate an indicatordetectable by a user which indicates the time remaining in themedicament dispensing program and/or the time remaining until the pumpassembly battery will require recharging. The present inventions alsoinclude the pump assembly and remote control in the apparatus on anindividual basis. The present inventions also include systems thatcomprise such an apparatus in combination with a medicament cartridgeand/or a cannula and/or a baseplate, as such cartridges, cannulas andbaseplates are described in the context of the examples herein, definedby the claims herein or known to those of skill in the art.

A method in accordance with at least one of the present inventionsincludes the steps of learning from a remote control the amount of timeremaining in a subcutaneous dispensing program and/or time remaininguntil a pump assembly battery will require recharging, determiningwhether or not removing a medicament cartridge from the associatedinfusion pump and replacing the removed medicament cartridge with a newmedicament cartridge at the end of the time remaining would beconvenient or inconvenient and/or determining whether or not rechargingthe pump assembly battery at the end of the time remaining would beconvenient or inconvenient, and replacing the medicament cartridgebefore the medicament cartridge is empty and/or recharging the pumpassembly battery before it requires recharging in response to adetermination that replacement at the end of the time remaining would beinconvenient.

The features and attendant advantages of the present inventions willbecome apparent as the inventions become better understood by referenceto the following detailed description when considered in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Detailed description of exemplary embodiments will be made withreference to the accompanying drawings.

FIG. 1 is an exploded perspective view of an exemplary infusion pump kitincluding an infusion pump system, with an infusion pump assembly, amedicament cartridge, and a baseplate, a cannula and two additionalbaseplates.

FIG. 1A is a schematic view showing use of an exemplary infusion pumpsystem.

FIG. 1B is a schematic view showing use of an exemplary infusion pumpsystem.

FIG. 2 is a precision graph showing dispensing performance.

FIG. 3 is an exploded perspective view of an exemplary medicamentcartridge.

FIG. 3A is an end view of the interior of an exemplary medicamentcartridge.

FIG. 4 is a section view taken along line 4-4 in FIG. 3.

FIG. 5 is an exploded perspective view of the cartridge portion of apressure sensor.

FIG. 6 is a section view of the cartridge portion of another exemplarypressure sensor.

FIG. 7 is a schematic block diagram of another exemplary pressuresensor.

FIG. 8 is a schematic block diagram of another exemplary pressuresensor.

FIG. 9 is a perspective view of a portion of the plunger in theexemplary medicament cartridge illustrated in FIG. 3.

FIG. 10 is a perspective view of the body portion of the plungerillustrated in FIG. 9.

FIG. 11 is a perspective view of the seal portion of the plungerillustrated in FIG. 9.

FIG. 12 is a section view of the plunger illustrated in FIG. 3.

FIG. 13 is a section view of another exemplary plunger.

FIG. 14 is a simplified view of medicament cartridge with a removal tab.

FIG. 15 is a perspective view of an exemplary pump assembly.

FIG. 16 is a bottom view of the exemplary pump assembly illustrated inFIG. 15.

FIG. 17 is perspective view of the exemplary pump assembly illustratedin FIG. 15 with a cartridge inserted.

FIG. 18 is a perspective view of an exemplary pump module.

FIG. 19 is a perspective view of the pump module illustrated in FIG. 18with the end gear cap omitted.

FIG. 20 is a plan view of an exemplary chassis.

FIG. 21 is a front exploded perspective view of the chassis of FIG. 20.

FIG. 22 is a rear exploded perspective view of the chassis of FIG. 20.

FIG. 23 is a section view of the pump module illustrated in FIG. 19 witha partially filled medicament cartridge positioned therein and a latchmechanism in a lock position.

FIG. 24 is a section view taken on line 24-24 in FIG. 23.

FIG. 25 is a section view of the pump module illustrated in FIG. 19 withan empty medicament cartridge positioned therein and the latch mechanismin an unlock position.

FIG. 26 is a section view taken on line 26-26 in FIG. 25.

FIG. 27 is an elevation view of a portion of the latch mechanismillustrated in FIGS. 23-26.

FIG. 28 is a section view of the lead screw, gear, thrust bearing andpusher portions of the pump module illustrated in FIG. 19.

FIG. 29 is a simplified view showing a switch that detects when aplunger pusher is in a home position.

FIG. 30 is a section view of an exemplary pump module with variousstructures omitted and medicament cartridge reservoir clamping forcesdisplayed.

FIG. 31 is a perspective view of an exemplary infusion pump system withthe pump assembly removed from the medicament cartridge, cannula andbaseplate.

FIG. 32 is a perspective view of an alternative exemplary chassis andlatch.

FIG. 33 is a section view of an exemplary pump assembly including thelatch illustrated in FIG. 32 in an unlatched state.

FIG. 34 is another section view of a pump assembly including the latchillustrated in FIG. 32 in an unlatched state.

FIG. 35 is another section view of a pump assembly including the latchillustrated in FIG. 32 in a latched state.

FIG. 35A is a section view taken along line 35A-35A in FIG. 35.

FIG. 36 is a simplified section view of another alternative latch in anunlatched position.

FIG. 37 is a simplified section view of the latch illustrated in FIG. 36in a latched position.

FIG. 38 is a simplified view showing an alternative mechanism thatbiases a medicament cartridge against the front wall of a chassis.

FIG. 39 is a schematic view of a motor and an encoder.

FIG. 40A is a schematic view of an optical encoder system.

FIG. 40B is a schematic view of another optical encoder system.

FIG. 40C is a schematic view of yet another optical encoder system.

FIG. 40D is a schematic view of still another optical encoder system.

FIG. 40E is a schematic view of another optical encoder system.

FIG. 40F is a schematic view of yet another optical encoder system.

FIG. 40G is a schematic view of a magnetic encoder system.

FIG. 40H is a schematic view of another magnetic encoder system.

FIG. 40I is a schematic view of yet another magnetic encoder system.

FIG. 41 is a section view of an exemplary pressure sensor arrangement.

FIG. 42 is another section view of the pressure sensor arrangementillustrated in FIG. 43.

FIG. 43 is a section view of an exemplary fall-off detector.

FIG. 44 is another section view of the fall-off detector illustrated inFIG. 43.

FIG. 45 is a section view of another exemplary fall-off detector.

FIG. 46 is a schematic representation of yet another exemplary fall-offdetector.

FIG. 47 is a schematic representation of still another exemplaryfall-off detector.

FIG. 48 is a perspective view of an exemplary infusion pump system withthe pump assembly and medicament cartridge removed from the cannula andbaseplate.

FIG. 49 is a perspective view of an infusion pump assembly, with amedicament cartridge therein, being attached to a battery rechargingdevice.

FIG. 50 is a graph showing recharging temperature during an exemplarybattery recharging method.

FIG. 51 is a schematic view of an exemplary infusion pump assemblycontroller.

FIG. 51A is a block diagram showing certain functional relationships ofthe battery charging system illustrated in FIG. 49 and the controllerillustrated in FIG. 51.

FIG. 52 is a flow chart showing an exemplary motor torque controlmethod.

FIG. 52A is a diagram of an exemplary motor driving bridge circuit.

FIG. 53 is a perspective view of an exemplary baseplate.

FIG. 54 is a section view of a portion of a system including thebaseplate illustrated in FIG. 53.

FIG. 55 is a bottom perspective view of the system illustrated in FIG.54 with the adhesive liner removed.

FIG. 56 is a perspective view of an exemplary cannula.

FIG. 57 is a section view of the cannula illustrated in FIG. 56 insertedthrough a cartridge and secured to a baseplate.

FIG. 57A is a section view of the baseplate illustrated in FIG. 57.

FIG. 58 is a perspective view of another exemplary cannula.

FIG. 59 is a section view of the cannula illustrated in FIG. 58.

FIG. 60 is a perspective view of a portion of an exemplary pump assemblyhousing.

FIG. 61 is a perspective view of a portion of an exemplary baseplate.

FIG. 62 is a perspective view of an exemplary baseplate and infusionset.

FIG. 63 is a section view of a portion of a system including thebaseplate illustrated in FIG. 62.

FIG. 64 is a perspective view of an exemplary baseplate.

FIG. 65 is a section view of a portion of a system including thebaseplate illustrated in FIG. 64.

FIG. 66 is a perspective view of a portion of an exemplary baseplate.

FIG. 67 is a perspective view of a portion of an exemplary baseplate.

FIG. 68 is a perspective view of a portion of an exemplary baseplate.

FIG. 69 is a bottom view of a portion of an exemplary pump assembly.

FIG. 70 is a perspective view of a portion of an exemplary baseplate.

FIG. 71 is a perspective view of a portion of an exemplary baseplate.

FIG. 72 is a perspective view of a portion of an exemplary baseplate.

FIG. 73 is a diagrammatic representation of exemplary baseplateidentification instrumentalities.

FIG. 74 is a diagrammatic representation of exemplary baseplateidentification instrumentalities.

FIG. 75 is a diagrammatic representation of exemplary baseplateidentification instrumentalities.

FIG. 76 is a diagrammatic representation of exemplary baseplateidentification instrumentalities.

FIG. 77 is a diagrammatic representation of exemplary baseplateidentification instrumentalities.

FIG. 78 is a diagrammatic representation of exemplary baseplateidentification instrumentalities.

FIG. 79 is a flow chart showing an exemplary medicament cartridgeremoval and replacement method.

FIG. 80 is a section view showing a medicament cartridge being insertedinto the exemplary pump assembly illustrated in FIG. 33.

FIGS. 81-83 are section views showing the pump assembly and cartridgeillustrated in FIG. 80 during an exemplary pusher zeroing procedure.

FIG. 84 is a section view showing the removal of a plug from thecartridge illustrated in FIG. 83 and the attachment of a body adherablebaseplate to the pump assembly.

FIG. 85 is a section view showing a cannula inserter, with a cannula,attached to the exemplary system including the pump assembly, baseplateand cartridge illustrated in FIG. 84.

FIG. 86 is a front view showing a patient's skin being cleaned.

FIG. 87 is a section view showing the system illustrated in FIG. 85 onthe cleaned skin prior to cannula insertion.

FIG. 88 is a section view showing the system illustrated in FIG. 87after cannula insertion.

FIG. 89 is a section view showing the system illustrated in FIG. 88 onthe skin with the cannula inserted and the inserter being removed.

FIG. 90 is a section view showing the system illustrated in FIG. 89dispensing medicament by way of the cannula.

FIG. 91 is a flow chart showing exemplary cartridge position check andpusher zeroing methods.

FIG. 92 is a flow chart showing an exemplary dispensing method withocclusion detection.

FIG. 93 is a flow chart showing a number of exemplary occlusiondetection methods that may form part of the dispensing methodillustrated in FIG. 92.

FIG. 94 is a flow chart showing an exemplary reverse rotation of anunpowered motor correction method.

FIG. 95 is a graph showing motor rotational speed during an exemplarymotor stopping method.

FIG. 96 is a flow chart showing an exemplary automatic plunger pusherretraction method.

FIG. 97 is a flow chart showing an exemplary gear assembly verificationmethod.

FIG. 98 is a perspective view of an exemplary remote control.

FIG. 99 is a block diagram of the exemplary remote control illustratedin FIG. 98.

FIG. 100 is a flow chart showing exemplary alarm conditions.

DETAILED DESCRIPTION

The following is a detailed description of the best presently knownmodes of carrying out the inventions. This description is not to betaken in a limiting sense, but is made merely for the purpose ofillustrating the general principles of the inventions.

The detailed description of the exemplary embodiments is organized asfollows:

I. Introduction

II. Exemplary System Overview

III. Exemplary Medicament Cartridges

IV. Exemplary Pump Assemblies

-   -   A. Exemplary Housings    -   B. Exemplary Pump Modules Overview    -   C. Exemplary Chassis    -   D. Exemplary Plunger Pushers and Drive Mechanisms    -   E. Exemplary Reservoir Clamping    -   F. Exemplary Cartridge Lock and Bias Apparatus    -   G. Exemplary Encoders    -   H. Exemplary Pressure/Occlusion Sensors    -   I. Exemplary Fall-Off Detectors    -   J. Exemplary Batteries and Battery Rechargers    -   K. Exemplary Alarms    -   L. Exemplary System Controllers    -   M. Exemplary Motor Control

V. Exemplary Baseplates and Cannulas

VI. Exemplary Baseplate Identification

VII. Exemplary Basic Operation

VIII. Exemplary Operational Methodologies

-   -   A. Exemplary Cartridge Position Check    -   B. Exemplary Pusher “Zeroing” Procedure    -   C. Exemplary Occlusion Detection    -   D. Exemplary Accounting For Unpowered Motor Reverse    -   E. Exemplary Motor Stopping    -   F. Exemplary Automatic Plunger Pusher Retraction Procedures    -   G. Exemplary Gear Assembly Verification Procedure

IX. Exemplary Remote Controls and Associated Methodologies

The section titles and overall organization of the present detaileddescription are for the purpose of convenience only and are not intendedto limit the present inventions.

It should also be noted here that the specification describes a widevariety of structures and methods, mainly in the context ofcartridge-based infusion pumps that are especially well-suited for thesubcutaneous delivery of very high concentration insulin (e.g., theU-500 insulin discussed below). Nevertheless, it should be appreciatedthat the present inventions are applicable to a wide variety of infusionpumps and medicaments. By way of example, but not limitation, many ofthe present inventions are also applicable to infusion pumps that arenot cartridge-based (e.g., pumps with refillable reservoirs and singleuse pumps). Also, although the illustrated embodiments may employ acartridge with a plunger, a fluid displacement device in the form of aplunger pusher, and a drive mechanism that includes a motor, other fluiddisplacement devices may include, regardless of the type of cartridge orreservoir employed, piston pumps (e.g., electromagnet pumps), MEMSpumps, peristaltic pumps and any other suitable pumps as well ascorresponding drive mechanisms. The present inventions are alsoapplicable to medicaments such as, for example, drugs to mask pain,chemotherapy and other cancer related drugs, antibiotics, hormones,GLP-1, Glucagon, various other drugs that include large molecules andproteins that may require a high level of delivery accuracy, as well asto relatively high concentration insulin (i.e., U-200 and above) such asU-400 insulin.

I. Introduction

From the perspective of most patients, two important aspects ofambulatory infusion pumps are size and convenience. As noted above, someambulatory infusion pumps are frequently intended to be worn on a belt,carried in a pocket, or otherwise supported within a holder of some kind(referred to collectively as “pocket pumps”). Such infusion pumpstransfer fluid from a reservoir to an infusion set by way of an elongatetube. Subcutaneous access may be obtained by way of a cannula in theinfusion set. Other ambulatory infusion pumps are intended to be adheredto the skin at the delivery site (sometimes referred to as “patchpumps”). Here, the cannula or other subcutaneous access device mayextend directly from the infusion device. Given these modes of use,patients typically prefer the pump to be as small as possible so thatthe pump will be more comfortable, less obtrusive, and less visible.

One commercially available ambulatory infusion pump is the OmniPod®insulin pump from Insulet Corporation in Bedford, Mass. The OmniPod®insulin pump has overall dimensions of about 62.5 mm×42.9 mm×17.7 mm,i.e., has an overall volume of about 47.5 cc, and has a reservoir volumeof about 2.0 cc. Although this pump is relatively small, many patientswould prefer an even smaller pump. Reducing reservoir volume is a simplemethod of reducing the overall size of an infusion pump. Unfortunately,when the volume of the reservoir is reduced, all other things beingequal, there is a corresponding reduction in convenience because thesmaller reservoir requires more frequent refilling or replacement.

The present inventors have determined that smaller reservoirs can beemployed, without a corresponding reduction in convenience, byincreasing the concentration of the medicament dispensed therefrom. Inthe exemplary context of insulin therapy, some conventional infusionpumps have reservoirs which hold 2 milliliters (ml) of U-100 insulin.U-100 insulin is an insulin containing 100 international units (IU) ofinsulin activity per 1 ml and, accordingly, the 2 ml reservoir stores200 IUs. One common insulin dose is 0.5 IU, which equates to a dispensedvolume of 5 microliters (μl) of U-100 per dose, 400 doses per 2 mlreservoir, and about 4.5 days of therapy at the common dosage. At leastsome conventional infusion pumps are capable of delivering 5 μl/dosewith a delivery accuracy level that is acceptable for relatively lowconcentration U-100 insulin.

Higher concentration insulins are, however, commercially available.Humulin® R U-500 insulin, which is available from Eli Lilly and Companyin Indianapolis, Ind., contains 500 IU/ml. Although the use of highconcentration insulin would facilitate the use of a much smallerreservoir (e.g., 300 IU in a 0.600 ml reservoir), and could result inmuch smaller pumps for a given number of dosages, the five-fold increasein insulin concentration (as compared to U-100 insulin) necessitates afive-fold increase in fluid delivery accuracy. U-500 insulin iscurrently administered by injection and with certain conventionalinsulin pumps for patients who require more than about 200 IU/day. Theaccuracy of certain conventional pumps is adequate for patients whorequire about 200 IU/day or more. For example, conventional insulinpumps generally alert the patient (e.g., with an alarm) whenapproximately 3 IUs of U-100 insulin are missed on delivery, whichcorresponds to 30 μl of missed delivery. Using U-500 insulin, the missedvolume for a 3 IUs alert is reduced to six μl due to the higher insulinconcentration, and conventional infusion pumps are not capable of thislevel of accuracy.

The present inventors have determined that there are a plethora offactors that must be addressed if the goal is to deliver 1 μl/dose at anacceptable level of delivery accuracy. For example, the six μl alertrequirement means that the present infusion pump assembly must be verystiff (or “low compliance”) to ensure delivery accuracy over allconditions of operating pressures, frictions, temperatures and so forth.In the context of the exemplary cartridges described below, thedisplacement may be about 1 IU of U-500 insulin per 0.001 inch ofstroke, i.e., 2.0 μl/0.001 inch of stroke. The present inventors havedetermined that factors which can contribute to accuracy/precisionduring drug delivery may include: rotational accuracy of gearform(wobble and gearform consistency); encoder resolution; motor backdrive;encoder consistency (rotational spacing); motor phase balance; and motorcontrol circuit excitation consistency (excitation pulse width accuracyand switch accuracy). The present inventors have determined that factorswhich can contribute to axial (error) movement under load may include:thrust bearing (internal movement); thrust bearing (slip in mount); leadscrew (axial deformation); nut-to-lead screw gearform deflection;plunger body compression; plunger body-to-seal axial slip; plungerseal-to-low friction layer axial slip; thrust bearing-to-lead screwaxial slip; cartridge body deformation/axial slip; leadscrew-to-transverse gear axial slip; lead screw-to-transverse gear axialslip; push rod-to-nut axial deformation; cartridge body hydraulicexpansion; sense diaphragm hydraulic deflection; infusion set hydraulicexpansion; cannula movement in cartridge extending or shortening fluidpath; and fluid path bubble compression. The relevance of many of thesefactors is discussed below in the appropriate contexts.

Another convenience related issue identified by the present inventorsrelates to the fact that a patient may desire to use a pocket pump insome instances and a patch pump in others. In addition to the addedexpense, switching between two different infusion pumps may adverselyeffect the patient's medicament delivery regimen. Notwithstanding thedesire of some patients to switch back and forth, the mere fact thatsome patients prefer a pocket pump while others prefer a patch pumpforces manufacturers to choose between designing, testing and obtainingapproval for two different pumps or simply staying out of one of themarkets.

II. System Overview

Exemplary ambulatory infusion systems, which are generally representedby reference numerals 10, 11 and 12 in FIG. 1, include a medicamentcartridge (or “cartridge”) 100, an ambulatory infusion pump assembly (or“pump assembly”) 200, and one of the baseplates 500, 501 and 502.Generally speaking, the cartridge 100 may be inserted into the pumpassembly 200 and the appropriate baseplate 500-502 may be secured to thepump assembly. To that end, and as discussed in greater detail inSection V below, the baseplates 500-502 in the illustratedimplementations are configured for different modes of system operation.Baseplate 500 is a body adherable baseplate that may be used inconjunction with a cannula (e.g., cannula 600 in FIGS. 56-57) that isdirectly connected to the cartridge 100 so that the system 10 may bedeployed as a “patch-pump” (FIG. 1A). Baseplate 501 is configured toconnect the cartridge 100 to an infusion set 503 so that the system 11may be deployed as a “pocket pump,” a “belt-worn pump” or some otherwearable pump (FIG. 1B). Baseplate 502 is a medicament non-deliverybaseplate that may be used to seal the cartridge 100 during periods ofnon-use (e.g., by way of plug 504), thereby defining a non-use system12.

In other words, using the same medicament cartridge (e.g., cartridge100) and pump assembly (e.g., pump assembly 200), the user may configurethe system for use as “pocket pump” or a “patch pump” by simplyselecting the appropriate baseplate 500 or 501 and attaching thebaseplate to the pump assembly. The user may also switch from oneconfiguration to another, in many instances without removing thecartridge from the pump assembly, by simply removing one baseplate andreplacing it with another baseplate.

Whether configured as a “pocket pump” or a “patch pump,” the system maybe configured to provide basal delivery of medicament in accordance witha delivery profile provided by a physician by way of a clinician'sprogramming unit. For example, the system may include a program thatstores a number of delivery profiles (e.g. delivery profiles associateda 24-hour delivery cycle and delivery profiles for particular situationssuch as sleep or illness). Each delivery profile specifies multipledoses (or pump “operations”) over time, e.g. a particular number ofdoses at particular times or a particular number of doses per unit time.In some implementations, a dose may be the volume associated with theminimum controllable displacement of a cartridge plunger. The system mayalso be configured to provide bolus delivery in response to aninstruction from a patient remote control. A bolus instruction may comein response to a high glucose level measurement in the case of adiabetic patient, an increase in pain level in the case of a painmanagement patient, or some other symptom. The system may also beconfigured to perform other functions, such as ending medicamentdelivery, in response to instructions from a patient remote control.

The parts of the present systems that do not come into contact withmedicament during normal operation (e.g., operation not associated witha cartridge that is damaged and leaking) may be considered the reusableparts, while the parts that do come into contact with medicament duringnormal operation, and may define portions of the medicament delivery (or“flow”) path, may be considered the disposable parts. In the illustratedembodiments, the pump assembly 200, which includes structures such asthe motor and various mechanical structures, the controller and thebattery (and may be more expensive), is reusable, while the cartridge100, baseplates 500-502 and cannula 600 (if any) are disposable.

The pump assembly 200 in the exemplary system 10 (and 11) does not comeinto contact with medicament because the cartridge 100, which isaccessible from outside the pump assembly 200, includes its ownmanifold. Medicament can, therefore, flow directly from the cartridgereservoir to the associated cannula or other device without contactingthe pump assembly. Such an arrangement is advantageous for a variety ofreasons. For example, portions of the medicament delivery path from thereservoir to the cannula (or infusion set tube) can become clogged orotherwise in need of repair. Such repair may be inconvenient and costlyin the context of many conventional infusion pumps because the pumpmechanism (e.g., a piston or peristaltic pump) is part of the medicamentdelivery path. The present systems obviate this unpleasant aspect ofsome conventional infusion pumps by removing the medicament flow pathfrom the reusable portion of the system. The present systems alsoprovide less expensive long term therapy, as compared to manyconventional systems, because the more expensive portions are reusable.

The infusion pumps described herein address the accuracy/precisionfactors and the axial movement factors noted above by providing a moreaccurate, less compliant infusion pump. For example, the constructionsof the cartridge (e.g., the inside diameter is constant, and the plungeris configured to be urged precisely in response to movement of the drivemechanism), the rigidity of the chassis and the precision of the drivemechanism, as well as the operation procedures of the drive mechanism,allow for an amount of medicament of 0.1% or less of the total filledvolume of the reservoir to be controllably dispensed with single-doseprecisions that range from plus or minus (+/−) 20% to +/−5%. Thisprecision can be obtained after a dispensing period of six to eighthours or less resulting in a dose accuracy of from +/−20% to +/−5%. Thedispensed amount can be as low as 0.23-0.27 μl/dose. The dose can bedispensed in as little as two seconds or less for small volumes, orlonger times for larger volumes such as those associated with basaldelivery.

For example, 300 units of U-500 insulin (0.6 mL or 600 μl) can beprovided in the reservoir of one of the cartridges described below, andwithin a two hour or less stabilization period, medicament can becontrollably dispensed from the cartridge with a precision of +/−5% andwith 0.5 unit per dose (1.0 μl/dose). As graphically illustrated in FIG.2, the ability to obtain a single-dose precision of better than +/−5% inas little as six to eight hours or less is vastly superior to thestandard set forth in the International Electrotechnical Standard (IEC)for the safety of infusion pumps and controllers (IEC 60601-2-24), whichprovides for a 24-hour stabilization period before precisionmeasurements are even taken. In other words, although the IEC 60601-2delivery test provides a twenty-four hour stabilization period duringwhich pump operation is allowed to be untested, the present pumps, froma clinical perspective, may be tested without such a stabilizationperiod. This “time-to-precision” superiority is especially important inthe context of high concentration medicaments because the adverseeffects of prolonged over-delivery or under-delivery are magnified. Forexample, a “time-to-precision” of six hours may be appropriate in thecontext of U-500 insulin and Type-1 diabetics who use basal rates ofless than one IU/hour.

The precision capabilities associated with the present system, and thecorresponding ability to use a very highly concentrated medicament(e.g., U-500 insulin) and relatively highly concentrated medicaments(e.g., U-200 to U-400 insulin) also facilitate, if so desired, a markeddecrease in ambulatory infusion pump size as compared to conventionalpumps. For example, one exemplary pump assembly 100 described below hasdimensions of about 40 mm×32 mm×11 mm, for an overall volume of about 14cc. This is considerably less than the approximately 47 cc overallvolume of the aforementioned OmniPod® insulin pump.

III. Exemplary Medicament Cartridges

The exemplary system is, as noted above, a cartridge-based system inthat medicament cartridges 100 are inserted into the pump assembly 200and later removed from the pump assembly. The cartridges 100 may alsobe, but are not required to be, prefilled and disposable. Prefilledcartridges are advantageous for a variety of reasons. By way of example,but not limitation, some users prefer to avoid cartridge fillingprocedures because they are inconvenient and tend to involve needles.User-based refilling also increases the likelihood that air bubbles willbe introduced into the cartridge, while prefilling by the manufacturerof the cartridge and/or the medicament can be accomplished without anysubstantial introduction of air bubbles using, for example, a vacuumfilling procedure. A lack of bubbles is very important in the context ofdosage accuracy in that air is compressible and liquid medicament isnot. For example, 20 μl of air will have a compressibility of about 6 μlat a 5 psi operating pressure, which can adversely effect pressuresensing in the system. If the system is configured to alert the user ofmissed dosing equal to approximately 6 μl (3 IUs for U-500 insulin), 6μl (3 IUs for U-500 insulin) will be delayed before there is a useralert. In addition, the presence of 20 μl of air in the cartridgeresults in the patient not receiving 10 IUs of U-500 insulin during thelife of the cartridge. Prefilled cartridges with less than 5 μl of airbubbles are preferred when U-500 is the stored medicament.

As illustrated in FIGS. 3 and 4, the exemplary medicament cartridge 100may include a body portion (or “barrel”) 102, which defines a medicamentreservoir 104, a plunger 106 that is held by friction within the bodyportion, and a manifold 108 that may be used to connect the reservoirto, for example, cannulas and baseplate structures in the mannerdescribed below with reference to, for example, FIGS. 57 and 63.Medicament is identified by reference numeral 101 in FIG. 23. Theplunger 106 is moved within the body portion 102 to vary the volume ofthe reservoir 104. In particular, the plunger 106 moves in a dispensingdirection where reservoir volume is decreased, but does notsubstantially move to increase volume during use of the cartridge 100.The cartridge 100 may also be provided with a plug 110 that preventsleakage from a prefilled reservoir 104 (e.g., prefilled in a vacuum withU-500 insulin) during packaging, shipping, storage and handling, and canbe used in a pusher zeroing procedure as described in Section VIII-Bbelow.

Referring first to the body portion 102, and although the presentinventions are not limited to any particular shape, the exemplary bodyportion 102 is cylindrical in overall shape and has a cylindrical innersurface 112 that defines the cylindrical reservoir 104 (FIG. 3). Thebody portion 102 and inner surface 112 may be other shapes in otherimplementations. By way of example, but not limitation, the overallshape of the body portion 102 and the shape of the inner surface 112 mayboth be oval in cross-section, or the overall shape of the body portionmay be rectangular and the shape of the inner surface may be oval orcircular in cross-section. The inner surface 112 may also be anon-curved, such as rectangular or square in cross-section.

The exemplary manifold 108 illustrated in FIGS. 3 and 4 has a bodyportion 114 that defines a through-bore 116 and the front wall 117 ofthe cartridge. The through-bore 116 is directly connected to arelatively short reservoir outlet port 118 (i.e., is connected withoutadditional tubing). The through-bore 116 and outlet port 118 facilitatea direct fluidic connection between the cartridge 100 and theaforementioned cannulas and baseplates that have a portion thereofinserted into the through-bore. The reservoir outlet port 118 may alsobe parallel to the direction of plunger movement (note FIG. 54). Such anorientation results in a short, direct and efficient medicamentdispensing path as the plunger 106 reduces the volume of medicament inthe reservoir 104.

Additionally, as illustrated in FIG. 4A, the inner surface of the bodyportion end wall 119, i.e., the wall that the plunger 106 abuts when thereservoir is empty, may include an annular recess 121 which trapsbubbles that may be present in the reservoir and prevents them fromexiting the cartridge 100. In one exemplary implementation, the annularrecess 121 is a 0.25 mm deep semi-circle in cross-section, is 0.5 mmfrom the circumferential edge of the outlet port 118, and is 0.5 mm wide(i.e., 0.5 mm from the ID to the OD). Such bubble entrapment reduces thelikelihood that bubbles will be dispensed and, accordingly, reduces thelikelihood that medicament dispensing and occlusion sensing will sufferbubble-related decreases in accuracy. Other ways to trap bubbles at theend wall 119 include, but are not limited to, concentric recesses,hydrophilic filters and elevated outlet ports.

At least some of the exemplary implementations may employ pressure datain various contexts. For example, a pressure sensor may be used todetect occlusions downstream from the reservoir outlet port 118 that areimpeding, or completely preventing, medicament flow. To that end, amedicament cartridge may include some or all of the pressure sensoritself. In the illustrated implementation, the cartridge 100 includesthe cartridge portion 120 of the pressure sensor 234 that is describedin Section IV-H below with reference to FIGS. 41 and 42. The pressuresensor may also be used to detect the presence of a cartridge in thepump assembly, as is also described below.

The exemplary pressure sensor cartridge portion 120 illustrated in FIGS.3 and 4 includes a pressure sensor housing 122, which may be integralwith (as shown) or otherwise connected to or carried by the manifold108, and a detectable structure 124. The detectable structure 124, whosemovement can be detected as described below, is mounted in a pressuresensor housing recess 126 and communicates with the through-bore 116 byway of an aperture 128 so as to expose the detectable structure to thefluid pressure in the through-bore. As shown in FIG. 5, the exemplarydetectable structure 124 has a deflectable part 130 with a magnet 132(e.g., a neodymium magnet), a resilient diaphragm 134 (e.g., a siliconediaphragm) that carries the magnet by way of a sleeve 136, and adiaphragm retention ring 138 (e.g., an olefin polymer retention ring).The exemplary detectable structure 124 also has a cap 140 with acylindrical abutment 142, a bore 144 in which the magnet 132 and sleeve136 are located, and a flange 146. During assembly, the detectablestructure 124 is inserted into the housing recess 126 until theretention ring 138 abuts the recess wall 148 (FIG. 4). The cap 140 isthereafter inserted into the recess 126 until the cylindrical abutment142 engages the retention ring 138 and the flange 146 is flush with thepressure sensor housing 122 (FIG. 1). The diaphragm 134, which isexposed to reservoir pressure by way of the aperture 128, flexes inresponse to pressure increases, such as during an occlusion event,thereby moving the magnet 132. The movement is sensed by the pumpassembly portion 236 (e.g., Hall-effect sensor or magnetoresistivesensor) of the pressure sensor 234 as described in Section IV-H belowwith reference to FIGS. 41 and 42. Thus, in this implementation, thecartridge portion 120 may be thought of as the “unpowered” portion ofthe pressure sensor 234 and the pump assembly portion 236 may be thoughtof as the “powered portion.” Moreover, the more expensive portion, e.g.,a sensor such as a Hall-effect or magnetoresistive sensor, is part ofthe reusable pump assembly 200.

Generally speaking, air (not medicament) acts on the diaphragm 134because of the air cushion formed between the plug 110 and diaphragmduring manufacture. That said, the sensor 234, which includes thecartridge portion 120, can detect a pressure change corresponding to sixμl of medicament (i.e., the three IU of U-500 insulin) or less ofplunged medicament that is being held up by a blockage. The six μl ofmedicament generally corresponds to the volume created by deflection ofthe detectable structure 124 (note FIG. 42).

Another exemplary cartridge portion of a pressure sensor is generallyrepresented by reference numeral 120 a in FIG. 6. The cartridge portion120 a may be part of a medicament cartridge 100 a that is otherwiseidentical to cartridge 100. Cartridge portion 120 a is substantiallysimilar to cartridge portion 120 and similar elements are represented bysimilar reference numerals. For example, the cartridge portion 120 aincludes a detectable structure 124 a. Here, however, the diaphragm 134a includes a post 136 a on which a cylindrical magnet 132 a is mounted.In other words, instead of the magnet 132 a being in a sleeve, thismagnet 132 a defines a sleeve. The diaphragm 134 a also includes anintegral mounting member 138 a that is press-fit into the recess 126with a cylindrical wedge 142 a.

It should also be noted that the present pressure sensors are notlimited to the type of devices described with reference to FIGS. 5 and6. By way of example, but not limitation, a cartridge portion 120 b(FIG. 7) may include a diaphragm that carries a magnetically permeablestructure 132 b which changes the inductance of a coil in the pumpassembly portion PAP of the sensor when moved relative thereto. Asimilar arrangement may employ an optical element and a correspondingoptical sensor, and FIG. 7 may also be considered a representationthereof (with the optical element represented by reference number 132b). Another exemplary pressure sensor may be in the form of anelectrical switch that includes a pump assembly portion PAP1 with a pairof switch contacts and a cartridge portion 120 c with a diaphragm whichcarries an electrical conductor 132 c that connects the contacts whenthe diaphragm moves a predetermined distance (FIG. 8).

With respect to dimensions, the exemplary cartridge 100 may beconfigured to have a reservoir 104 whose volume is less than or equal toabout 1000 μl and, some implementations, between about 500-700 μl. Forperspective, and as noted above, a 600 μl (0.600 ml) reservoir wouldstore 300 units of U-500 insulin, which corresponds to about one week'sworth of insulin for a patient using approximately 40 IU of insulin perday. Such volumes may achieved by way of a body portion 102 with aninner diameter of 9.8 mm, with a tolerance+/−1.0 mm in some instancesand a tolerance of +/−0.1 mm in others, an outer diameter of 11.8 mm,with a tolerance+/−1.0 mm in some instances and a tolerance of +/−0.10mm in others, a stroke length (i.e., the distance that the plunger 106travels from the full position to the empty position) of 8.5 mm+/−2.0mm, and a length of 17.5 mm, with a tolerance of +/−1.0 mm in someinstances and a tolerance of +/−0.10 mm in others.

It should be noted here that the stroke length to inner diameter ratioof the present reservoir 104 may be about 1.0 or less. For example, insome implementations, the ratio may be 0.86, or may range from about0.75 (or less) to about 1.0.

The plunger may play a substantial role in the dosage accuracyassociated with the present system. The exemplary plunger 106illustrated in FIGS. 3 and 9-12 includes a plunger body 150, a seal 152,and a friction reduction layer 154 that provides a low coefficient offriction between the friction bearing surface of the plunger 106 andbarrel inner surface 112.

Referring more specifically to FIGS. 10 and 12, the plunger body 150 maybe spool-shaped, in that it is a solid structure with a recessed middleportion 156 and circumferential rings 158. The recessed middle portion156 and circumferential rings 158 extend circumferentially around theaxis A (FIG. 12). Indentations 159 may be provided for a portion of thefriction reduction layer 154. The spacing between circumferential rings158 and the barrel inner surface 112 may be relatively small, i.e.,there is close tolerance, to minimize plunger wobble. For example, thediameter of the rings 158 may be about 9.7 mm with a tolerance of+/−0.06 mm and the spacing can be 0.10 mm with a tolerance of +/−0.073mm in some instances and a tolerance of +/−0.12 mm in others. Theplunger body 150 also has forward and rearward facing (relative to thedirection of plunger travel during medicament dispensing) surfaces 160and 162. Put another way, with reference to the medicament in thereservoir 104, the surface 160 is the “wet side” and surface 162 is the“dry side.” The forward facing surface 160 may be provided with aconcave recess 164 that is at least substantially aligned with thereservoir outlet port 118. A generally annular indentation 165 extendsinto the plunger body 150 from the rearward facing surface 162. Inaddition to reducing the weight of the plunger 106, the indentationfacilitates removal of the plunger body from the mold duringmanufacture.

In other implementations, the plunger body may be planar on the wetand/or dry sides. Such a plunger body would resemble the simplifiedillustration of plunger body 150 in FIG. 34. The plunger body surfacesinterfacing with the inner surface of the barrel may also becylindrical, that is, planar in cross section as opposed to rounded.

Referring to FIGS. 10-12, the seal 152 may be located between theplunger body 150 and the friction reduction layer 154, and within theplunger body recessed middle portion 156 between the circumferentialrings 158. As such, the seal 152 in the illustrated implementation actson the plunger body 150, as well as the friction reduction layer 154,and is radially and axially constrained. The seal 152, which may includean annular base portion 166 and a pair of o-rings 168, also providesenough force to press the friction reduction layer 154 outwardly againstthe inner surface 112 of cartridge body 102 and establishes a seal thatwill hold under the pressures associated with the present systems andmethods. Moreover, given the radial and axial constraints, the amount ofseal compression (and the resulting sealing force) is more predictablethan it would be otherwise.

The seal 152 is under radial and axial compression forces which providea sealing load on both the friction reduction layer 154 and the plungerbody 150. The radial and partial axial compression forces also force thefriction reduction layer 154 outward against the cartridge barrel innersurface 112. Overcompression is undesirable as the resultant seal has awide range of static/running forces, so compression is engineered to bewithin a predictable range.

The seal 152 may also be provided with a plurality of protrusions 170(FIGS. 11 and 12), such as integrally molded protrusions, on the forwardfacing surface 172 (as shown) and/or on the rearward facing surface (notshown). The protrusions 170 ensure that the seal 152 is axially stable(or properly constrained) between the plunger body circumferential rings158, and will typically be compressed into the annular base portion 166as shown in FIG. 12. Constraining the seal 152 in this manner makes itmore likely that the seal will accurately track movement of the plungerbody 150 and, in turn, facilitates accurate reduction in reservoirvolume. The protrusions 170 also prevent overcompression of theexemplary seal 152 in the plunger body 150, which could lead tounpredictable seating and unpredictable forces on the friction reductionlayer 154 and, therefore, on the cartridge barrel 102.

It should also be noted here that the plunger 106 in the illustratedembodiment is not connectable (or “is unconnectable”) to the plungerpusher 250 (note FIGS. 45-47) that pushes the plunger forwardly towardthe outlet port 118. Put another way, and referring to FIG. 12, theplunger body 150 does not include any structural components that are (orcould be) connected to the plunger pusher. For example, the plunger body150 does not include an unthreaded opening, a threaded opening, afastener, a magnetic catch, a ratchet, or other such instrumentality.The dry side of the plunger body could also be planar (and noted above).Given the lack of connectability, under no circumstances will reversemovement of the plunger pusher 250 pull the plunger 106 rearwardly anddraw medicament back and air (if any) into the reservoir 104. Theplunger 106 can only move forwardly when being contacted by, and/or dueto operation of, the plunger pusher 250.

Although there are numerous possible configurations that would not beconnectable to a plunger pusher, the exemplary plunger body 150 simplyhas a smooth rearward facing surface 162 that may be planar (as shown inthe simplified illustrated presented in FIG. 34) or curved.Additionally, or alternatively, the plunger pusher 250 (note FIGS. 18,23 and 25) may be unconnectable to the plunger, as is discussed inSection IV-D below, for the same reasons.

With respect to materials, the body portion 102, manifold 108 andplunger body 150 of the exemplary cartridge 100 may be formed fromplastic, glass or a combination of glass and plastic, and the seal 152may formed from rubber, such as bromobutyl rubber. The body portion 102and manifold 108 may be integrally formed, or formed separately andjoined to one another (e.g., by ultrasonically or laser welding). Onesuitable plastic is cyclic olefin polymer (COP). It should be noted,however, that the particular medicament that is to be stored in thecartridge 100 should be taken into account. For example, each milliliterof Humulin® R U-500 insulin contains 500 units of biosynthetic humaninsulin, 16 mg glycerin, 2.5 mg Metacresol as a preservative, andzinc-oxide calculated to supplement endogenous zinc to obtain a totalzinc content of 0.017 mg/100 units. Sodium hydroxide and/or hydrochloricacid may be added during manufacture to adjust the pH. Otheringredients, such as phenol (preservative), surfactants, and bufferingagents may be added as required. As such, Humulin® R U-500 insulin maybe better suited for long term storage in glass than it is for long termstorage in plastic. In those instances where storage in a plasticcartridge (e.g., a COP cartridge) is desired due to the inherentadvantages of plastic as compared to glass (e.g., lighter, lessexpensive and more durable), a bioequivalent of Humulin® R U-500 may beemployed. Here, the formulation of Humulin® R U-500 may be adjusted toincrease the stability of the insulin by, for example, changingpreservative, changing stabilizers, and changing buffering agents.

In at least some implementations, the cartridge body portion 102 may beformed from transparent glass, transparent COP or some other suitabletransparent material. There are a variety of advantages associated witha transparent cartridge body portion 102. For example, as shown in FIG.17 and discussed in Section IV below, the pump assembly 200 andcartridge 100 are respectively configured such the body portion 102 willprotrude through an opening 226 in the housing top wall 214 when thecartridge is inserted into the pump assembly. In one implementation, thecartridge 100 will protrude less the one mm (which equates to fivepercent of the volume of reservoir 104). The patient will be able to seethe medicament in reservoir 104 and readily determine, when for examplethe medicament is insulin, whether or not the medicament is cloudy(which indicates a loss of effectiveness), as well as roughly estimatewhat portion of the original medicament volume remains in the reservoir.

The friction reduction layer 154 in the exemplary embodiment may beformed in a variety of ways. The friction reduction layer 154 may be,for example, a polytetrafluoroethylene (PTFE) sleeve that is shrinkwrapped over the plunger body 150 and seal 152 (as shown in FIG. 12).Ethylene tetrafluoroethylene (ETFE) and fluorinated ethylene propylene(FEP), which are in the same family as PTFE, may also be employed.Alternately, the friction reduction layer 154 can be implemented as alow friction coating or surface modification of the seal 152. Coatingscould be formed from a fluorinated polymers such as FEP and PTFE. Whencombined with a COP cartridge body portion 102 and the otherabove-described aspects of the plunger 106, the present frictionreduction layer 154 provides a break force (static friction) of lessthan five pounds and running forces (dynamic friction) of two to four orfive pounds.

As to the exemplary plug 110 illustrated in FIG. 3, and as alluded toabove, the plug is a removable sealing device that is inserted into thecartridge through-bore 116 during manufacture to prevent leakage from aprefilled reservoir 104, by way of the outlet port 118, duringpackaging, shipping, storage and handling. The plug 110 will typicallyremain in place in the through-bore 116 until the cartridge 100 is inplace within the pump assembly 200 and is ready for medicamentdispensing. At that point, the plug 110 will be manually removed by theuser. Although the plug 110 is not limited to any particularconfiguration, the implementation illustrated in FIG. 3 includes abulbous head 174 and a stem 176. The head 174 may have a disk portion178 and a plurality of gripping protrusions 180, while the stem 176 mayhave a plurality of spaced sealing rings 182 carried on a cylindricalmember 184. Suitable material for the plug 110 includes, but is notlimited to, bromobutyl rubber. An internal core (not shown), such as afiber core, may be provided in some instances in order to prevent theplug from ripping during manual removal subsequent to the pusher zeroingprocedure described in Section VIII-B below.

In some instances, long term interaction between the medicament and thepressure sensor diaphragm (e.g., diaphragm 134) during shipping andstorage may be problematic. Accordingly, in at least someimplementations, the respective configurations of the cartridge 100 andplug 110 are such that the pressure sensor aperture 128 will be isolatedfrom the reservoir outlet port 118 by a portion of a fully insertedplug. For example, at least one of the sealing rings 182 may be betweenthe pressure sensor aperture 128 and reservoir outlet port 118 when theplug is fully inserted.

Another exemplary plunger, which is generally represented by referencenumeral 106 a in FIG. 13, includes a plunger body 150 a, a forward(relative to the direction of travel) o-ring seal 152 a, and a frictioncontrol device 152 b that is spaced from the o-ring seal. The frictioncontrol device 152 b may be in form of an o-ring (as shown) or in theform of an overmolded part in some embodiments. The friction controldevice 152 b provides for a consistent, reliable resistance of theplunger 106 a to pushing force (e.g., from the plunger pusher) and maybe configured such that at least one pound of force is required to pushand move the plunger. This functionality may be accomplished in avariety of ways. For example, the o-ring seal 152 a and friction controldevice 152 b may be formed from different materials, and/or may bedifferently shaped, and/or may be differently sized. For example theo-ring seal 152 a may be made of chlorobutyl rubber or bromobutylrubber, and the friction control device 152 b of silicone orpolytetrafluoroethylene.

At least some embodiments of the present pump assembly 200 include alatch or other mechanism that prevents the cartridge 100 from simplyfalling out of the pump assembly when the associated baseplate isremoved. Here, a small amount of pushing force (via the top opening 226in FIG. 15) and/or pulling force (via the insertion opening 218 in FIG.16) is used to remove the cartridge. Turning to FIG. 14, a medicamentcartridge (e.g., cartridge 100) may be provided with a pull tab 186 thatallows the user to pull the cartridge from the pump assembly 200 and/orsimply makes the cartridge easier to grasp in those instances wherepulling force is not required. In the illustrated example, the pull tab186 has a main portion 188 that is firmly secured to the cartridge 100and a handle portion 190. The handle portion 190 may include a low tackadhesive to hold it to the cartridge body until the time of use.Alternatively, the handle portion 190 may simply hang free or may bepushed out of the way (shown by dotted lines). Instead of and/or inaddition to the pull tab 186, an outward bias device (such as one ormore springs) may be mounted to the cartridge or within in the cartridgecompartment. Pull-out ribbons may also be provided.

IV. Exemplary Pump Assemblies

Briefly, the exemplary pump assembly 200 may include an external housing(“housing”), which is generally represented by reference numeral 202 inFIG. 15, and a pump module, which is generally represented by referencenumeral 204 in FIG. 18, that is located within the housing. Otherstructures that may be carried within the housing 202 include, but arenot limited to a rechargeable battery 238, a circuit board controller240 and an alarm 242, as are illustrated in FIG. 18. When the medicamentcartridge 100 is inserted into the pump assembly 200, as illustrated inFIG. 23, the cartridge plunger 106 of the medicament cartridge 100 willbe proximate to and facing the plunger pusher 250 of the pump module204. The drive mechanism 252 of the pump module may then drive thepusher 250 relative to the cartridge plunger 106 to controllably andprecisely dispense medicament from the cartridge reservoir 104.

A. Exemplary Housings

Referring first to FIG. 15-17, the housing 202 has a top portion 206 anda bottom portion 208. The top portion 206, which includes two side walls210, two end walls 212, a top wall 214 and rounded corners therebetween,generally defines the internal volume in which the pump module 204 andother pump assembly components are carried, as well as the overallvolume of the pump assembly 200. The bottom portion 208 includes abottom wall 216, which functions as a cover for most of the internalvolume, and an insertion opening 218 in the bottom wall through whichthe cartridge 100 is inserted into the cartridge receiving (or“cartridge storage”) area 220. The outer surface of the top wall 214defines the “top face” or “top surface” of the housing 202, and theouter surface of the bottom wall 216 defines the “bottom face” or“bottom surface” of the housing. In the illustrated embodiment, theinsertion opening 218 abuts a thin rim 356 that is flush with theexterior surface of the bottom wall. The rim 356 is part of the chassis244 (FIG. 14) of the pump module 204.

The configuration of the pump assembly 200 generally, and the housing202 and insertion opening 218 in particular, is such that the cartridge100 is inserted through the insertion opening 218 and into the cartridgereceiving area 220 in a direction that is normal to plunger pusher 250,as well as the axis along which the plunger pusher travels (note FIGS. 1and 80).

The top wall 214 of the housing 202 may also be provided with one ormore openings. For example, a through-bore opening 224 may be providedin the housing top wall 214 to provide access to the cartridgethrough-bore 116 (FIGS. 3-4). Such access may be required during acannula insertion process, such as that described below with referenceto FIGS. 45-48.

The top wall 214 of the housing 202 may also be provided with an opening226 for the cartridge body 102 (or “cartridge body opening 226”) in someimplementations. The through-bore opening 224 and cartridge body opening226 are merged into a single cartridge opening in the illustratedembodiment. Such openings may be separate in other embodiments. Asalluded to in Section III in the context of the exemplary cartridge 100,an opening facilitates observation of the medicament and plunger in acartridge formed from transparent material. Additionally, in theillustrated embodiment, the pump assembly 200 is configured (i.e.,sized, shaped, etc.) such that a portion of the associated cartridge(e.g., cartridge 100) may protrude through the cartridge body opening226 when the cartridge is in the cartridge receiving area 220. Forexample, the relative configurations of the cartridge 100 and pumpassembly 200 may be such that the cartridge body 102 protrudes slightly(e.g., about 0.40-1.00 mm, or five percent of the reservoir volume)through the opening 226 in the housing top wall 214, as is illustratedin FIG. 17. The cartridge body inner surface 112 will, however, belocated below the inner surface of the top wall 214. The length of thecartridge body opening 226 is substantially equal to the length of thecartridge body 102, with appropriate clearance, while the width issomewhat less than the diameter of the cartridge body. For example, thewidth of the opening 226 may be about 60 to 90% of the diameter and isabout 83% in the illustrated implementation.

One important advantage of the cartridge/pump assembly relationshipdescribed in the preceding paragraph is size reduction. Allowing aportion of the cartridge 100 to protrude through the cartridge bodyopening 226 eliminates the need to accommodate that portion of cartridgebelow the inner surface of the housing top wall 214, which in turnallows for a reduction in the overall thickness (or “profile”) of thepump assembly 200. The reduction is equal to the sum of the length ofthe protrusion, the thickness of the housing top wall 214, and anyclearance that would have been necessary between the inner surface ofthe top wall and the cartridge in a “cartridge enclosed” implementation.In the context of ambulatory infusion pumps, where every reduction insize is important, this is a significant savings.

The pump assembly 200 may also be configured (i.e., sized, shaped, etc.)such that a portion of the associated cartridge (e.g., cartridge 100)protrudes through the insertion opening 218 on the bottom surface of thehousing 202 when the cartridge is in the cartridge receiving area 220.In such an implementation, the associated baseplate (e.g., baseplate500) may be provided with an aperture 508 (or a recess) to accommodatethe protruding portion of the cartridge as is discussed in Section Vbelow with reference to FIGS. 53-55. Typically, although notnecessarily, the cartridge 100 will not protrude substantially beyondthe bottom surface of the baseplate or will not protrude beyond thebottom surface of the baseplate at all. Protrusion of the cartridgethrough the insertion opening 218 affords the same size relatedadvantages as the cartridge opening 226 in the housing top wall 214,which is to reduce the thickness of the housing 202.

A plurality of electrical contacts 228, 230 and 232 may extend through(or be carried on) the housing bottom portion 208, as is illustrated inFIG. 16. As discussed in greater detail in Sections IV-J and VI below,two of the contacts (e.g., contacts 228 and 230) may be used toelectrically connect the pump assembly 200 to a battery recharger (e.g.,charger 700 in FIG. 49) and all of the contacts, at least in someimplementations, may be used by the pump assembly during a baseplateidentification procedure described.

With respect to dimensions, some embodiments of the exemplary housing202 may have the following dimensions: length dimensions of 42 mm+/−1.0,42 mm+/−0.10, 40+/−1.0 mm, 40+/−0.10 mm or 40+/−5.0 mm; width dimensionsof 34 mm+/−1.0, 34 mm+/−0.10 mm, 32 mm+/−1.0 mm, 32 mm+/−0.10 mm or 32mm+/−5 mm; overall thickness or height dimensions of 11 mm+/−1.0 mm or11 mm+/−0.10 mm; and wall thickness dimensions on the order of 1.0mm+/−0.10 mm. Suitable housing materials include, but are not limitedto, plastic or other materials having a modulus of elasticity of 0.2-1.0million psi.

B. Exemplary Pump Module Overview

As noted above with reference to FIG. 15, internal components of theexemplary pump assembly 200 may include, among other things, the pumpmodule 204, rechargeable battery 238, circuit board controller 240 andalarm 242. Exemplary pump modules are described below with reference toFIGS. 18-39. Other components may include the pump assembly portion 236of a pressure sensor.

C. Exemplary Chassis

Briefly, and referring first to FIG. 18, the exemplary pump module 204may have a rigid chassis 244, which is configured to form a cartridgecompartment 246 that defines the cartridge receiving area 220, a plungerpusher (or “pusher”) 250 that drives the cartridge plunger 106 (FIG. 25)in the dispensing direction, and a drive mechanism 252 that drives theplunger pusher in the dispensing (or “forward”) direction and theretraction direction. The rigid chassis 244 may, among other things,provide a low compliance, very rigid mounting structure for receivingand securely holding the medicament cartridge 100 relative to theplunger pusher 250, and is shown in FIGS. 23 and 25.

The chassis 244, and thereby the pump module 204, may be molded snap in,hooked, bonded or attached with fasteners to the bottom portion 208 ofthe pump assembly housing 202. As can be seen in FIG. 16, when thechassis 244 is positioned in the housing 202, the large bottom opening248 directly communicates with the medicament cartridge receiving area220. The exemplary chassis 244 also includes an opposing, and smaller,top opening 254 that directly communicates with the top wall opening 226in the housing 202, as shown in FIGS. 15 and 17.

Turning to FIG. 20, the components of the exemplary chassis 244, whichis described in extensive detail below, may include a first side framemember 256, a second side frame member 258, an end gear cap 260, twolong fasteners 262, two shorter fasteners 264, a connector bar 266 (FIG.21), and two spring bias clips 268. The exemplary rigid chassis 244 isshown in exploded form in FIGS. 21 and 22 to illustrate the variouschassis components and the assembly thereof.

The first side frame member 256 illustrated in FIGS. 21 and 22 mayinclude a first side longitudinal portion 270, a rear transverse dog leg272, a bulging portion 274, a first forward recessed area 276 definingpart of the cartridge compartment 246 and a first forward transverseportion 278 defining another part of the cartridge compartment 246. Thelongitudinal portion 270 has an outer elongate recessed area 280 endingat the bulging portion 274, which has a through-hole 282. A first half284 of a circular longitudinal opening 350 (FIG. 18) may be formed atthe rear of the cartridge compartment 246 by the first side frame member256. The longitudinal portion 270 may have a side through-opening orwindow 287 at a forward location in the cartridge compartment 246. Insome embodiments, the opening 287 may be sealed with a transparent coversuch as a transparent film. The dog leg 272 may have two large fasteneropenings (or “holes”) 286 and two small fastener openings 288 in arearward face 290. Engagement portion 292 extends inwardly from thelongitudinal portion 270 and the forward transverse portion 278 and intothe cartridge compartment 246. The forward transverse portion 278 mayhave a side opening 294. Top and bottom body plate portions 296, 298extend inwardly from the longitudinal portion 270, forwardly from thedog leg 272 and rearwardly from the cartridge compartment 246.

The second side frame member 258 illustrated in FIGS. 21 and 22 mayinclude a second side longitudinal portion 300, a second forwardrecessed area 302 defining part of the cartridge compartment 246 and asecond forward transverse portion 304 defining part of the cartridgecompartment 246 and having a transverse through-hole 306. An engagementportion 308 extends into the cartridge compartment 246 from the secondside longitudinal portion 300 and the second forward transverse portion304. As shown in FIG. 21, two spaced recessed areas 310 may be formed onthe inward surface of the second side longitudinal portion 300 and atthe cartridge compartment 246, and lateral through-openings 312 may beformed at upper ends of these recessed areas, as can be seen in FIG. 22.A second half 314 of the large longitudinal opening 350 may be formed atthe rear of the cartridge compartment 246, as shown in FIG. 21. Alongitudinal through-opening 316 may be near the second half 314 of theopening, as can be seen in FIG. 21, and through a wall 318 of the secondside frame member 258. The wall 318 forms a portion of the aft wall 320(FIG. 18) of the cartridge compartment 246. The rear end of the secondside frame member 258 may include a wall 322 extending between top andbottom body plate portions 324, 326 and inward from the second sidelongitudinal portion 300. As can be seen in FIG. 22, the wall 322 mayinclude upper and lower openings 328, 330.

It may be noted here, with reference to FIGS. 16 and 17, that thechassis engagement portions 292, 308 at least in substantial part definethe periphery of the top opening 254 of the chassis 244. The engagementportions 292, 308 may also form abutment surfaces for the medicamentcartridge 100 to block a top surface of the medicament cartridge fromimpacting the housing 202 as a small portion of the cartridge extendsthrough the housing opening 226 (FIG. 17).

The exemplary end gear cap 260 illustrated in FIGS. 21 and 22 may beformed by a body portion 332 having a bulging portion 334 and a flatinward back face 336. Referring to FIG. 21, the inward back face 336 mayinclude two small recess openings 328, 330, a first one in the bulgingportion 334 and a second one close to the first one, as well as acentral circular large recess opening 338. The outward rear surface ofthe body portion 332 may have two recessed wells 340, each communicatingwith respective through-openings 342, and two recessed wells 346, eachcommunicating with respective through-openings 348, as shown in FIG. 21.

The configuration of the exemplary chassis 244 allows the chassis to besubsequently disassembled and reassembled in order to, for example,retrieve, repair and/or replace components of the pump module 204.

The assembly of the chassis components can be understood from acomparison of FIGS. 21 and 22 to FIGS. 18 and 20, with an emphasis onthe dotted lines in FIGS. 21 and 22. The order of the assembly steps maybe varied from those set forth below as would be apparent to thoseskilled in the art. Operative positions of the components of the drivemechanism 252 (FIG. 18) and drive line 344 (FIG. 25) in and relative tothe chassis 244 are described below with reference to FIGS. 23 and 25,for example.

As part of the exemplary assembly method, bottom ends of the springclips 268 are fitted into (or otherwise affixed in) bottom ends of therespective recessed areas 310. The clips 268 are compressed slightly andtheir upper ends are inserted into the upper ends of the respectiverecessed areas 310 and into the respective openings 312. The clips 268are thereby compressed and bulging slightly into the cartridgecompartment 246, as can be seen in FIGS. 18 and 19. Thus, when themedicament cartridge 100 is in the cartridge compartment 246, the springclips 268 bias the cartridge 100 to and against the opposite wall of thecartridge compartment. This not only helps to insert and releasably holdthe cartridge 100 in the cartridge compartment 246, but also pushes thecartridge 100 closer to the chassis window 287 to hold occlusion sensorcomponents in fixed relation as is discussed in detail in Section IV-H.

The first and second side frame members 256, 258 are positioned togetheras part of the chassis assembly process. When positioned together, theconnector bar 266 is inserted in through the through-hole 306 and intothe opening 294 to thereby connect the first and second transverseportions 278, 304 together. Alternatively, the connector bar 266 may beinserted into the through-hole 306, the first and second side framemembers 256, 258 positioned together and the connector bar 266 thenpushed into the opening 294.

With the first and second side frame members 256, 258 positionedtogether and the end gear cap 260 positioned against the rearward face290 of the dog leg 272 of the first side frame member 256, it can beunderstood from the drawings that many of the holes or openings willalign for operative insertion therein of respective fasteners.Specifically, and referring to FIG. 22, holes 286, 330, 342 will alignfor receipt therein of fasteners 262 with the heads 263 disposed in thewells 340; and holes 288, 348 will align for receipt therein offasteners 264 with the heads 265 disposed in the wells 346. The heads263 and 265 are disposed in their respective wells, and do not extendout exposed beyond the outer surface envelope of the end gear cap 260,as can be seen in FIG. 20.

Referring to FIG. 22, the two longer fasteners 262 pass throughrespective holes 342 in the end gear cap 260 and the first and secondside frame members 256, 258. In contrast, the two shorter fasteners 264do not extend into the second side frame member 258, but only throughholes in the end gear cap 260 and the first side frame member 256. Thisarrangement has the advantage that the fasteners 262, 264 not onlyattach the gear cap 260 to the first and second side frame members 256,258, but also attach aft ends of the side frame members together and ina relatively compact construction.

When the chassis 244 is assembled, the first and second halves 284, 314(FIG. 21) adjoin to form the circular longitudinal opening 350 (FIG.18). The opening 350 extends between the cartridge compartment 246 andthe chassis chamber 352 illustrated in FIG. 21. The top surface ofchamber 352 is formed by the adjoining top plate portions 296, 324 andthe bottom surface is formed by the adjoining bottom plate portions 298,326. The opening 316 (FIG. 18), which is adjacent to the opening 350,also extends between the cartridge compartment 246 and the chamber 352.

As can be understood from the drawings, including FIGS. 18, 19 and 20,the bulging portions 274, 334 of the first side frame member 256 and theend gear cap 260, respectively, are similarly configured such that whenthe end gear cap 260 is attached to the first side frame member 256 thebulging portions 274, 334 mate and form a continuous smooth curvingsurface.

The cartridge compartment bottom opening 248 (FIG. 18), which is formedwhen the first and second side frame members 256, 258 are mated, mayhave a generally rectangular shape with three right angle corners andone rounded corner 354, which is shown in the bottom perspective viewsof FIGS. 18 and 20. The bottom opening 248 may be formed or defined by arim 356, as shown for example in FIGS. 19 and 20 and described above.The opening 248 and the cartridge compartment 246 itself may beconfigured to receive therein with a relatively close fit the medicamentcartridge 100. The opening 248, cartridge compartment 246 and medicamentcartridge 100 may be configured so that there advantageously is only oneorientation in which the cartridge 100 may be inserted into thecartridge compartment 312.

With respect to materials, the chassis 244 may be made, for example, ofceramic, plastic filled with a stiffening material, glass-reinforcedplastic, carbon reinforced plastic, aluminum, steel, titanium or othermetal. The chassis 244 may be formed of a material having a modulus ofelasticity greater than 1 million psi, 3 million psi, 10 million psi or10-30 million psi. This is considerably more rigid than the material ofthe housing 202 itself. Turning to dimensions, in some implementations,the chassis 244 may have a length of 40 mm+/−1.0, 40 mm+/−0.10 mm or37.0-41.0 mm; a thickness of 9 mm+/−1.0, 9 mm+/−0.10 mm or 8.9-9.1 mm;and a width of 16 mm+/−1.0, 16 mm+/−0.10 mm, or 15.8-16.2 mm. Thecartridge compartment 246, in turn, may have a length of 19 mm+/−1.0, 19mm +/−0.10 mm or 18.8-19.2 mm and a width of 12 mm+/−1.0, 12 mm+/−0.10mm or 11.8-12.2 mm. The cartridge compartment 246 also may help shieldthe medicament 101 (FIG. 23) in the medicament cartridge 100 from heatgenerated by the rechargeable battery 238 (FIG. 18) during dispensingand/or recharging procedures.

As an example, the configuration and construction of the present chassis244 may contribute to a frame and drive line rigidity sufficient towithstand axial loads to ten pounds without extension greater than0.0005 inch through 200,000 rotational (turns) cycles or 400 axialcycles. Axial cycles refer to the nut 364 traveling down the lead screw360 (discussed below with reference to FIGS. 23 and 25).

D. Exemplary Plunger Pushers and Drive Mechanisms

The exemplary pump module 204 illustrated in FIG. 18 includes, as notedabove, a plunger pusher 250, to push the cartridge plunger 106 in thedispensing direction, and a drive mechanism 252 that drives the plungerpusher. Generally speaking, the exemplary drive mechanism 252 may, insome instances, include a motor 358, a lead screw 360 (FIG. 23), a gearassembly 362 (FIG. 19) operatively between the motor and the lead screw,a drive nut 364 (FIG. 23) attaching the pusher to the lead screw, and athrust bearing 370 (FIG. 23). Each of these components is discussed ingreater detail below.

As illustrated for example in FIG. 23, the exemplary plunger pusher 250may be a hollow, generally cylindrical structure that includes a plungerengagement surface 366. The pusher 250 may, in some instances, have aflange (not shown) that prevents rotation of the pusher with the leadscrew 360. Additionally, as noted in Section III above in the context ofexemplary medicament cartridge 100, the exemplary pusher 250 may beconfigured such that it is not connectable (or “is unconnectable”) tothe cartridge plunger 106. Put another way, and referring to FIG. 23,the exemplary plunger pusher 250 does not include any structuralcomponents that are (or could be) connected to the plunger pusher. Forexample, the plunger pusher does not include external threads, afastener, a magnetic catch, a ratchet, or other such instrumentality.The plunger engagement surface 366 may, for example, simply be planar asshown. Given the lack of connectability, under no circumstances willreverse movement of the plunger pusher 250 pull the plunger 106rearwardly and draw medicament back into the reservoir 104.

Suitable materials for the plunger pusher 250 include, but are notlimited to, stainless steel, polystyrene and polycarbonate. Thedimensions will correspond to the other aspects of the overall system.For example, the plunger pusher 250 may have an outer diameter (or other“thickness” dimension of 6 mm+/−1 mm and a length of travel of 8.5mm+/−2.0 mm.

With respect to the drive mechanism 252, and referring first to themotor, and although the present inventions are not limited to anyparticular motor, the exemplary motor 358 may be a stepper motor suchas, for example, the Faulhaber ADM 0620 motor. The Faulhaber ADM 0620motor has a 6 mm diameter, a planetary gearhead of 256 reduction, andthe specifications of the motor are set forth at www.faulhaber.com. Astepper motor may in some instances control angular displacement andspeed more precisely than a DC motor. Motors other than stepper motors,including DC motors, may be employed in the present pump assemblies.

Turning to the lead screw, and referring to FIG. 23, the exemplary leadscrew 360 is connected to the plunger pusher 350 by a drive nut (or“retaining nut”) 364 such that the rotational motion of the lead screw360 may be translated into axial movement of the pusher 250. In otherwords, the drive nut 364 is in contact with the lead screw 360 andpropels the pusher 250. The exemplary drive nut 364 may be molded withthe pusher 250 or may be pressed into a flange of the pusher.Alternatively, the pusher 250 and drive nut 364 may be integrallymachined of the same material or the pusher may be molded with internalthreads.

The lead screw 360 and the drive nut 364 may be made of material thatallows axial movement within an exemplary 0.0005 inch overall chassis“stretch” budget under a ten pound load through 200,000 rotationalcycles or 400 axial cycles. The lead screw 360 may have a gearformaccuracy in rotation of better than 0.0005″ to prevent apparent misseddelivery increment, and may have a 70% mechanical efficiency. Thediameter of the lead screw 360 may be relatively small (e.g., 3.0 mm) tohelp minimize the size of the pump module 204. The threads 368 of theexemplary lead screw 360 may be Acme threads to provide high efficiencyand precision, and may have a 0.5 mm lead pitch (approximately 0.020inch/revolution).

An exemplary drive line 344 may be defined, as is illustrated in FIG.28, by the retaining nut 364, lead screw 360 and thrust bearing 370. Thethrust bearing 370 may be on the non-threaded shaft end 372 of the leadscrew 360. The thrust bearing 370 may also be selected, for example, toallow axial movement within an exemplary 0.0005 inch overall chassis“stretch” budget under a 10 pound axial load, and have an axial lengthof 2 mm, an inner diameter of 2 mm and an outer diameter of 6 mm.

The thrust bearing may be a conventional ball bearing, angular contactbearing, or, as illustrated in FIG. 28, it may be a combinedradial/thrust bearing of the type represented by reference numeral 370.The thrust bearing 370 may include ball bearings 374, a retainer 376that guides the ball bearings, a thrust washer 378, and radial ballbearings 380 that ride on the thrust washer and also ride on a thrustface of a drive gear 382. The radial ball bearings 380 may take up thethrust of the lead screw 360 in the retraction direction. The drive gear382 may be integrally machined with, or welded or bonded to, a portionof the lead screw 360 such as the non-threaded shaft end 372. The radialbearings 384 may be pressed onto the shaft 372 and, to resist axialforce, pressed or bonded into the rear wall of the chassis 244 or morespecifically into the opening 338 (FIG. 21) in the gear cap 260. As anexample, the combined radial/thrust bearing 370 may be configured toresist ten pounds of axial force during medicament 101 dispensing fromthe medicament cartridge 100 and four pounds of axial force duringretraction of the pusher 250.

Turning to FIG. 19, which shows the exemplary pump module 204 with thegear cap 260 removed therefrom for explanatory purposes, the drive gear382 on the lead screw 360 is one of three gears of a transverse geartrain 384. The other two gears may be a planetary gearbox output gear386 and a transverse gear 388 that is operatively positioned between thedrive gear 382 and the output gear 386. As illustrated in FIG. 21, theshaft 390 of the transverse gear 388 is fixed in the gear cap opening392 and the gear 388 freely rotates on the shaft 390. The gear cap andfirst side member bulging portions 336, 274 define part of a gear boxfor the transverse gear train 384. Lubricant may be provided in the gearbox to reduce the friction between the gears therein.

The transverse gear train 384 may be selected to withstand gearformloads of 10 mNm output torque at the motor 358. The accuracy of thegearform in rotation may be better than 0.0005 inch to prevent apparentmissed delivery increment (decremented by the gear ratio closer to themotor output). The transverse gear train 384 may have a 2:1 gear ratio.

The exemplary gear assembly 362 may also include a planetary gearbox394. The planetary gearbox 394 may be selected to withstand gearformloads of 10 mNm output torque at the motor 358, and may have a 256:1gear ratio.

As illustrated for example in FIGS. 18 and 19, the drive mechanism 252may also include an encoder 396 positioned on the shaft of motor 358opposite the planetary gearbox 394. The encoder 396 may be used todefine/resolve the number of revolutions (or “angular displacement”)and/or the rotational direction of the motor shaft. Thedisplacement/direction information is sent to the controller 240 andused to control various operations of the pump assembly 200, as isdiscussed in greater detail in Section IV-L (among others) below.Briefly, during normal operation, the controller 240 sends paired drivesignals to the motor 358 (stepping pulses) while monitoring the pulsetrain back from the encoder 396. For example, the number of encodersignals (or “ticks”) for a particular dispensing operation may becalculated, encoder 396 is monitored in near real time to determine ifit is moving as predicted. The encoder 396 may also be used to detectgear assembly issues as well as motor operation errors.

As is also illustrated in FIGS. 18 and 19, the motor 358, planetarygearbox 394, and encoder 396 together define a cylinder. The cylinderfits in a compact manner partially into and against the outer recessedsurface 280 of the chassis first side frame member 256. Turning to FIGS.23 and 25, when viewed in plan, the exemplary drive mechanism 252defines a U-shape with one leg of the U being defined by thelongitudinal axis of the motor 358, planetary gearbox 394, and encoder396, while the other leg of the U is defined by the longitudinal axis ofthe lead screw 360. The two axes (or legs of the U) are only 9.5+/−1.0mm apart in the illustrated embodiment. The base of the U is defined atleast substantially by the transverse gear train 384.

In at least some instances, it may be desirable to detect when theplunger pusher 250 is in the fully retracted (or “home”) positionillustrated in FIGS. 18 and 29. This may be accomplished in a variety ofways. One exemplary structure for performing the retracted positiondetection function is the position detector 398 illustrated in FIG. 29.The exemplary position detector 398 includes a switch 400, which may bemounted to the chassis 244 aft of the opening 350, and a flange 402 thatmay be carried by the pusher 250. When the pusher 250 is in theretracted position illustrated in FIG. 29, the switch 400 is closed bythe flange 402 and sends a signal to the controller 240 indicating thatthe pusher 250 is in the home position. The switch is open when thepusher 250 is not in the home position and a portion thereof is withinthe cartridge compartment 246.

In other embodiments, different types of switches may be employed, orthe flange may be omitted and the switch positioned such that it will beclosed by the pusher 250 when the pusher 250 is in the retractedposition. For example, switch contacts (e.g. a metalized pattern) may becarried on the chassis 244 and a conductive pad may be carried on theflange 402. Non-mechanical detectors, such as magnetic detectors andoptical detectors, may be used in place of a switch. Additionally,regardless of the type of detector employed, the detector may beconfigured to provide a signal to the controller 240 when the pusher 250is not in the retracted position.

Another alternative is to simply detect that the motor encoder 396 isnot turning when running the motor 358 in reverse. To that end, a hardmechanical stop (not shown) may be provided at a location that stops thepusher 250 and stalls drive mechanism 252 when the pusher reaches thehome position. Such a hard mechanical stop may be non-binding, i.e.,configured such that the drive mechanism 252 can be stalled by the stopbut can also easily reverse without mechanism binding. Homing may beaccomplished by retracting the pusher 250 with controlled torque andspeed until the pusher hits the hard mechanical stop, thereby stallingthe motor 358. Motor stall may be identified in response to the encoder396 indicating no rotation. The expected stall (home) location may beremembered by the device and compared to the actual stall position foradditional control or, in at least some implementations, the motor 358may be given a reverse displacement command that is larger than thetotal possible travel of the drive mechanism 252, and the actual stall(home) position determined based on the stall of the motor. The varioustechniques described herein for increasing motor torque in response to amotor stall to verify stall position may be employed to improve thistechnique of home position determination by stalling at the hard stop.

E. Exemplary Reservoir Clamping

The arrangement, configuration and materials of the chassis 244 anddrive line 344 in the exemplary implementation together create a force“clamp” that is generally represented by reference numeral 404 in FIG.30. The clamp 404 clamps the reservoir 104 between the dry side of theplunger 106 and the outer surface of the cartridge front wall 117. Putanother way, both ends of the reservoir 104 are held in such a mannerthat movement of the reservoir relative plunger pusher 250 (e.g., due tocartridge movement) may be prevented, and the corresponding loss ofdelivery accuracy prevented.

The thick arrow 406 in FIG. 30 represents the action force associatedwith the pusher 250 pushing the plunger 106 as a result of rotation ofthe motor 358. The thin arrows 408 show the reaction forces originatingin the plunger 106, traveling back in the opposite direction through thedrive line 344 and then forward through the fasteners 262 and 264, andthrough the chassis 244 to the front wall 117 of cartridge 100. Areaction force 410 on the outer surface of the front wall 117 andopposite to the action force 406 is thereby created. The force “clamp”404 may be generally configured as a pair of oppositely-facing C-shapedclamps, as can be understood from FIG. 30.

The clamping displacement of the reservoir 104 applied by the clamp 404adjusts incrementally as the cartridge plunger 106 is advanced towardsthe front wall 117 by the pusher 250. For example, the clampingdisplacement may adjust incrementally by 0.001 inch. The exemplary clamp404 may apply a clamping displacement with, for example, a precision ofbetter than 2% over a force range of zero to ten pounds.

F. Exemplary Cartridge Lock and Bias Apparatus

In at least some implementations, structure is provided to block removalof a cartridge from the pump assembly when the plunger pusher 250 is inthe cartridge 100, and to allow a cartridge to be inserted into andremoved from a compartment within the pump assembly when the pusher isretracted.

One example of such as structure is the releasable, linear one-wayclutch (or a “latching mechanism,” or an “interlock”) that is generallyrepresented by reference numeral 412 in FIGS. 23-27. The clutch 412blocks removal of a cartridge (e.g., cartridge 100) from the pump module204 when the plunger pusher 250 is in the cartridge, but allows thecartridge to be inserted into and removed from the cartridge compartment246 when the pusher is in a retracted “home” position.

Referring first to FIG. 24, the exemplary clutch 412 may include a firstcoil spring 414, a first pin or elongate member 416, a second coilspring 418, a second pin or elongate member 420, and a “teeter-totter”toggle ball 422. The second elongate member 420 may includefriction-engaging surface 428 (FIG. 27). The first coil spring 414 ispositioned inside of the first elongate member 416 to form aspring-biased first member 424. The second coil spring 418 is positionedin the second elongate member 420 to form a spring-biased second member426.

In one exemplary implementation, the first and second springs 414, 418may each have one to two pounds of spring force. The first spring 414may have a one mm diameter, and the second spring 418 may also have aone mm diameter. The first and second elongate members 416, 420 may haverespective lengths of 12.5 and 7.25 mm. The second elongate member 420may be a two mm diameter steel rod, and the friction-engaging surface428 may be a two to five degree beveled surface.

With respect to operation of the exemplary clutch 412, the mode of thespring-biased first member 424 determines whether the clutch 412 is in alocked condition (FIGS. 23 and 24) or an unlocked condition (FIGS. 25and 26). The spring-biased second member 426, when the pusher 250 is ina non-retracted position, holds the spring-biased first member 424 in afriction-contact locked condition with the friction-engaging surface428. The cartridge 100 is thereby latched in place in the cartridgecompartment 246.

The toggle ball 422 toggles when the pusher 250 is moved to theretracted home position. The toggling action moves the spring-biasedsecond member 426 to a position with the friction-engaging surface 426out of friction contact with the spring-biased first member 424. In thisunlocked or unlatched condition (FIGS. 25 and 26), the cartridge 100 maybe removed from or inserted into the cartridge compartment 246. In thisfully retracted mode, the spring-biased first member 424 retracts whenthe spring force of the first coil spring 414 therein is overcome by theforce of a cartridge 100 being inserted into or removed from thecartridge compartment 246.

The spring-biased first member 424 may have a patterned end 430 with asixty-degree beveled face 432 on the cartridge insertion side, as shownin FIG. 24 for example. This beveled face 432 facilitates easy cartridgeinsertion, with a radius where the spring-biased first member 424engages the cartridge 100 in a small slot (not shown) for detent action.FIG. 18 shows the end 428 of the spring-biased first member 424protruding or extending into the cartridge compartment 246 with thesixty-degree beveled face 432 disposed upwards. So positioned, thespring-biased first member 424 will engage the inner surface 112 (FIG.23) of the cartridge medicament cartridge when the medicament cartridgeis in the cartridge receiving area and, given the close fit between theexterior of the cartridge and the interior of the chassis, removal willbe prevented.

More particularly, when the clutch 412 is in the locked conditionillustrated in FIGS. 23 and 24, the second member 426 intersects thefirst member 424 at generally five degrees with a light spring force of0.1 to 0.5 pound, biasing the spring-biased second member 426 towardsthe spring-biased first member 424. That is, the second member 426 isspring biased towards the first member 424, and thereby operates similarto a one-way roller clutch. Referring to FIG. 24, the first member 424is on top with the second member 426 below and intersecting at generallyfive degrees with the light spring bias of 0.1 to 0.5 pound. With thepusher 250 in any position other than the fully retracted home position(FIG. 25), the second member 426 is self-energized by friction with thefirst member 424, thereby preventing rearward motion of the first member424. Then, when the pusher 250 is in a fully retracted position, thesecond member 426 is moved slightly forward by the half ball toggle 422,releasing friction contact with the first member 424. The spring-biasedfirst and second members 424, 426 are thereby in the positions shown inFIG. 26.

In other words, when the pusher 250 is fully retracted, the first member424 is biased towards the cartridge 100 with a one to two pound springforce and acts like a spring plunger detent. In this fully retractedmode, the first member 424 is able to retract when the spring force isovercome by cartridge insertion or removal. Then when the pusher 250 isnot fully retracted, the second member 426 locks the first member 424from rearward motion and blocks cartridge insertion and removal.

The half ball toggle 422 may be formed from a two mm diameter steelball, and may rest in a spherical recess 434, such as one machined intoa surface of the chassis 244. The half ball toggle 422 thereby cantoggle the second member 426 forward when the pusher 250 retracts fullyand engages the half ball toggle 422, as can be understood from thearrows 436, 438, 440 in FIG. 23. Other toggling or “teeter-totter”constructions may be used instead of the exemplary half-ball toggle 422.The clutch 412 also self-adjusts for cartridge 100 tolerance.

The pusher 250 and the spring-biased first member 424 may be providedwith o-ring sealing surfaces (not shown) to help make the clutch 412waterproof.

The pusher 250 may be retracted automatically when the reservoir 104 isempty (see FIG. 25) as discussed elsewhere in this disclosure, whichthereby automatically causes the clutch 412 to be unlocked when thereservoir is empty. Alternatively, by operating the remote control 1000(see, e.g., FIG. 81), the patient may cause the pusher 250 to beretracted before the reservoir 104 is empty, as when he wants to removethe medicament cartridge 100 before it is empty and replace it with anew cartridge 100. This retraction of the pusher 250 by the patient'sinstructions also causes the clutch 412 to unlock.

Another way of describing the mechanism of the clutch 412 is that themechanism functions as an interlock that prevents removal of themedicament cartridge 100 from the receiving area 220 when the cartridge100 is in the inserted position and the pusher 250 is in a non-retractedposition, and that allows removal of the medicament cartridge 100 fromthe receiving area 220 when the cartridge 100 is in the insertedposition and the pusher 250 is in a retracted position. Theinterlock/clutch 412 automatically unlocks the cartridge 100 when thepusher 250 is in the retracted position, and automatically locks thecartridge 100 when the pusher 250 is advanced out from the retractedposition.

Additionally, one exemplary advantage of the aforementioned light springbias is illustrated in FIG. 31 in the context of system 10. When a userof the exemplary patch pump system 10 desires to replace the cartridge100, baseplate 500 and cannula 600, the pump assembly 200 may simply bepulled off the baseplate. The baseplate adhesive (discussed below) willhold the baseplate 500 to the skin, the cannula latch (discussed below)will hold the cannula to the baseplate, and frictional engagementbetween the cannula and the cartridge through-bore will hold thecartridge to the cannula. In other words, the reusable portion of thesystem readily and conveniently separates from the disposable portions.

A further way to view the operation of the clutch 412 is that byoperating the remote control 1000, a cartridge-biasing member (thespring-biased first member 424) may be changed from a blockingcondition, where the cartridge-biasing member (the spring-biased firstmember 424) blocks removal of a medicament cartridge 100 from the pumpmodule 204, to a release condition, where the cartridge-biasing member(the spring-biased first member 424) does not prevent the medicamentcartridge 100 from being removed from the pump module 204. The clutch412 biases the cartridge 100 forwards, acts as a spring plunger detentduring insertion of the cartridge 100 into the compartment 246, andprevents backwards motion during use.

When in a locked condition, the spring-biased first member 424 mayengage and bias the medicament cartridge 100 forward in the cartridgecompartment 246. The cartridge 100 is thereby biased to a “held”position to secure the cartridge 100 firmly in place, such as against arigid wall of the chassis, for accurate and precise medicamentdispensing. The first member 424 may bias the cartridge 100 forward andthereby closer to the chassis window 287 (see FIG. 20) to fix therelative positions of various occlusion sensor components, as discussedelsewhere in detail in this disclosure.

Another exemplary structure that blocks removal of a cartridge from thepump assembly when the plunger pusher is in the cartridge, and allows acartridge to be inserted into and removed from a compartment within thepump assembly when the pusher is retracted, is the sliding latchmechanism (or “sliding latch”) generally represented by referencenumeral 412 a in FIGS. 32-35A. The exemplary latch 412 a is describedbelow in the context of the pump assembly 200′ and baseplate 500′, whichare identical to pump assembly 200 and baseplate 500 but for minoraccommodations for the latch 412 a, and similar elements are representedby similar reference numerals. With respect to the minor accommodations,which are discussed below in context, the pump assembly housing 202′includes a bottom portion 208′ with a latch slot 209, the chassis 244′includes minor adjustments, the plunger pusher 250′ includes a recess468, and the baseplate 500′ includes a latch indentation 509.

The sliding latch 412 a is configured to secure the cartridge 100 inplace when the pusher 250′ is at least partially in the cartridge 100,such as during the dispensing process. In addition to securing themedicament cartridge 100 within the pump module 204′, the sliding latch412 a biases the cartridge forward to a “held position” against therigid chassis front wall 245 when the pusher 250′ is at least partiallyin the cartridge 100. Such biasing facilitates accurate and precisemedicament dispensing, and ensures that the cartridge will be accuratelylocated relative to the chassis window 287 (FIG. 20).

Turning to the components of the exemplary sliding latch 412 a, andreferring to the bottom perspective view presented in FIG. 32, thesliding latch includes a slidable latch member 442 with a bottom lateralbody member 444 as well as a pair of legs 446 (one shown) extending upfrom opposite ends of the body member. A pair of abutment tabs 448respectively extend rearwardly from the legs 446. The bottom lateralbody member 444 includes a pair of flange portions 452 and an arched(convex) finger tab 456, with friction ridges 458, that is operativelyaccessible to the user when no baseplate attached (FIGS. 33 and 34).

A pair of rods 460 (one not shown) extend longitudinally through holesin the legs 446 and the front ends of the rods are secured in a wall ofthe chassis 244, such as the aft wall 320 (FIG. 18). The rear ends ofthe rods 460 are secured in a chassis flange 462. A pair of bias springs464 (one not shown) respectively encircle the rods 460 between the legs446 and the flange 462, and bias the slidable latch member 442 forward,towards the chassis cartridge compartment 246 and to a normal forwardbiased position.

When the latch member 442 is in the normal forward biased position, theends of the flange portions 452 will extend over the opening of thecartridge compartment 246, thereby blocking insertion of a medicamentcartridge (e.g., cartridge 100) into the pump assembly 200′ as well asthe removal of cartridge from the pump assembly. When the pusher 250 ais in a retracted home position, the slidable latch member 442 isunlocked (as discussed below) and the user can slide the latch memberrearward against the bias force of springs 464 (FIGS. 32 and 33) withinthe housing slot 209. The latch member 442 reaches the rearward positionwhen the tabs 448 abut the rear flange 462 (FIG. 32). Here, the flangeportions 452 no longer overlap the opening of the cartridge compartment246 and block insertion (or removal) of a cartridge.

Turning to FIG. 33, the exemplary sliding latch 412 a may also include alocking apparatus 466. The exemplary locking apparatus 466 may include arecess 468 in the plunger pusher 250′, a recess 470 in the lateral bodymember 444, a hole 472 in the chassis 244′, and a movable ball 474carried within the hole. When the latch 412 a is in the stateillustrated in FIG. 33, which is the result of the user sliding thelateral body member 444 to the rearward position, the movable ball 474will be located within the pusher recess 468. After a cartridge 100 isinserted into the cartridge compartment 246 and the user releases thelateral body member 444, the springs 464 will push the lateral bodymember to the position illustrated in FIG. 34. Here, movable ball 474will be aligned with both the pusher recess 468 and the lateral bodymember recess 470. Depending on the rotational orientation of the pumpassembly 200′, the movable ball 474 will either be in the pusher recess468 or the lateral body member recess 470. When the baseplate 500′ isattached as shown in FIG. 35, the user will no longer have access to thelatch 412 a and the finger tab 456 will be located in the baseplaterecess 509 (FIG. 35A). After the plunger pusher 250′ is moved forwardlyby operation of the lead screw 360, the movable ball 474 will be held inthe lateral body member recess 470 and, given that a portion of the ballis also in the chassis hole 472, the lateral body member 444 will heldin place and the latch 412 a will be in the locked state. The user willnot be able to unlock the latch 412 a until the pusher 250′ is returnedto the home position.

It should be noted that the relationship between the finger tab 456 andthe baseplate slot 509 also helps to facilitate proper alignment of thebaseplate 500′ relative to the pump assembly 200′ and, for example,proper alignment of the structures that are associated with thebaseplate identification process (described in Section VI below withreference to FIGS. 66-78) on the pump assembly (e.g., electricalcontacts 228, 230 and 232 in FIG. 16) and the baseplate (e.g.,identification devices 582-0, 582-1 and 582-2 in FIG. 1).

Another exemplary structure that blocks removal of a cartridge from thepump assembly when the plunger pusher is in the cartridge, and allows acartridge to be inserted into and removed from a compartment within thepump assembly when the pusher is retracted, is the sliding latchmechanism (or “sliding latch”) generally represented by referencenumeral 412 b in FIGS. 36 and 37. The latch 412 b may be used inconjunction with, for example, the cartridges, pump assemblies andbaseplates described herein with the minor accommodations describedbelow. The exemplary latch 412 b is described below in the context ofthe cartridge 100′, which is identical to cartridge 100 but for minoraccommodations for the latch 412 b, and the pump assembly chassis 244.Similar elements are represented by similar reference numerals. Withrespect to the minor accommodations, which are discussed below incontext, the cartridge body 102 includes a slot 478 and the chassis wall318 includes a longitudinal aperture 486.

The exemplary latch 412 b may include a latch element 476, which iscarried by the chassis 244, and is biased to a retracted, unblockingposition by a spring 480. In the illustrated embodiment, the latchelement 476 includes a flange portion 482 and a thinner extensionportion 484. The spring 480 may be positioned between the chassis wall318 (or some other fixed structure) and the flange portion 482. Thethinner extension portion 484 extends through the longitudinal aperture486.

The latch assembly 412 b may also include a sliding latch tensioner 488that slides relative to the pusher 250 along a longitudinal axis of thepusher. A flange or other structure 490 may be secured to, or be anintegrally formed part of, the pusher 250 and may be positioned aft ofthe sliding latch tensioner 488. A tensioner spring 492 may be disposedbetween the sliding latch tensioner 488 and the flange 490. Thetensioner spring 492 may be stronger than the latch spring 480. As thepusher 250 is driven into and against the plunger 106, the latch spring480 compresses quickly, propelling the extension portion 484 into thecartridge slot 478 (FIG. 37), thereby preventing the cartridge frommoving in a direction orthogonal to the longitudinal axis of the plunger250. The tensioner spring 492 absorbs additional propelling energy. Thebiasing force of the spring 480 pulls the extension portion 484 out ofthe cartridge slot 478, thereby unlocking the latch, when the plunger250 returns to the home position (FIG. 36).

The clutch 412 (FIGS. 16-20) and the sliding latch mechanism 412 a(FIGS. 27-27C), in addition to performing latching/locking functions,also perform a pushing function. The latch assembly 412 b (FIGS. 36-37)may be adapted to perform a pushing function. They all are examples ofstructures that perform the function of pushing (or “biasing”) amedicament cartridge (e.g., cartridge 100) against a wall and, morespecifically, engaging an aft end of a cartridge and pushing themedicament cartridge that is in the inserted position within the pumpassembly against a rigid wall to a held position. The rigid wall may,for example, be the front wall of the chassis 244. Other examplesstructures that performing these function are schematically representedby reference numeral 494 in FIG. 38. Such structures include, but arenot limited to, coil springs, leaf springs, interfering bumps,interference fits, and deformable resilient members. Such structures maybe attached to the aft wall 320 of the cartridge compartment 246 or someother structure.

G. Exemplary Encoders

One aspect of present system control instrumentalities, which isapplicable to variety of individual control methodologies discussedherein, is monitoring the actual movement of the shaft of motor 358.Specifically, the number of revolutions (or “angular displacement”)and/or the rotational direction of the motor shaft is resolved. Forpurposes of simplicity, rotation of the shaft of the motor is simplyreferred to as rotation of the motor. The number of revolutions in theforward direction may be used to determine the amount of medicament thathas been dispensed. For example, in some implementations, 14.4revolutions may equal one μL and, accordingly, may equal 0.50 IU ofU-500 insulin dispensed.

A wide variety of apparatus may be used to monitor angular displacementand rotational direction of the motor 358 so that the controller 240can, for example, determine if the motor is moving as predicted.Although the present inventions employ an encoder to perform thisfunction, other apparatus that may be employed include, but are notlimited to, monitoring coil current of the motor. It should also benoted that the present inventions are not limited to any particular typeof encoder.

In the exemplary embodiments, an encoder 396 may be positioned on theshaft of motor 358 in the manner illustrated, for example, in FIG. 18.The motor/encoder relationship is schematically represented in FIG. 39and various exemplary encoders are described below with reference toFIGS. 40A-40I. Briefly, during normal operation of at least oneembodiment, the controller 240 sends paired pulse/phase drive signals(stepping pulses) to the motor 358 while monitoring the pulse train backfrom the encoder 396. The pulse trains associated with exemplaryencoders are also presented in FIGS. 40A-40I. The encoder 396 ismonitored in near real time to determine if its movable portionassociated with the motor shaft 357 (and, therefore, the motor 358) ismoving as predicted.

Referring to FIG. 40A, an exemplary encoder 396 a may be an opticalencoder. Such encoders may have a light emitter 397, a photodetector399, and one or more optical interrupters 401. The interrupters 401 arepositioned and/or configured so that a different waveform is producedwhen the portion of the encoder 396 a with the interrupters is rotatedin a forward direction as opposed to a rearward direction, as shown. Theoptic interrupters 401 in the exemplary encoder 396 a are in the form oftwo occluding tabs spaced apart at an angle other than 180 degrees.Turning to FIG. 40B, exemplary encoder 396 b has two encoder openings401 b spaced apart at an angle other than 180 degrees. An exemplaryencoder 396 c with two reflective surfaces 401 c, also spaced apart atan angle other than 180 degrees, is shown in FIG. 40C. The exemplaryencoder 396 d in FIG. 40D has a single encoder opening 401 d with anasymmetrical shape that forms different forward and reverse waveforms.The occluding tab 401 e in exemplary encoder 396 e (FIG. 40E) is alsoasymmetrical and the waveform produced thereby is different in theforward and reverse directions. The exemplary encoder 396 f in FIG. 40Fhas openings 401 f of different size that result in a waveform that isdifferent in the forward and reverse directions.

Turning to FIGS. 40G-40I, other exemplary encoders employ magneticdetectors. Such encoders may include a sensor that senses changes inmagnetic fields, such as a Hall-effect sensor or a magnetoresistivesensor, and a magnet arrangement on or rotating with the motor shaft toproduce magnetic fields that are different in the forward and reversedirections of rotation. To that end, the exemplary encoder 396 gillustrated in FIG. 40G includes a sensor 403 and a magnet arrangement405 g, with S-N-S magnetized domains, that produces the illustratedsignal waveform. The exemplary encoder 396 h (FIG. 40H) includes amagnet arrangement 405 h with S-N-S magnetized domains and N-S-Nmagnetized domains. Another exemplary encoder, which is generallyrepresented by reference numeral 396 i in FIG. 401, has a rotation axisthat passes through a two-bar magnet arrangement 405 i. Anotherexemplary encoder 396 j is illustrated in FIG. 51. Here, the rotatingportion 405 j includes a single magnet and there is a pair of sensors403 a and 403 b. Another exemplary encoder may be in the form of anoptical encoder with a pair of sensors.

H. Exemplary Pressure/Occlusion Sensors

As discussed in Section III above, pressure sensors may be provided to,among other things, detect occlusions in a cannula or infusion set tube.Occlusions may occur for any number of reasons including, but notlimited to, cannula kinks caused by movement of the pump assemblyrelative to a deployed cannula, kinks in the infusion set tube, orgranuloma formation at the outlet end of a cannula. The structures thatare used to sense pressure may also be used to, for example, sensemedicament cartridge presence and alignment within a pump assembly. Inat least some implementations, one portion of the pressure sensor may bepart of the medicament cartridge and another portion of the pressuresensor may be part of the pump assembly. With respect to the medicamentcartridge pressure sensor portions, a variety of different embodimentsare described in Section III above with reference to FIGS. 3-8. Also,although the term “pressure sensor” is employed because pressure tendsto increase when fluid is pumped into a lumen that is completely orpartially occluded, the sensor may simply be a device that responds to apredetermined threshold pressure or a predetermined increase in volumewithin a particular region, as opposed to a sensor that is capable ofmeasuring various pressures within a range of pressures. Also, actualpressure need not be determined. For example, for a sensor that iscalibrated to produce a predetermined range of outputs over apredetermined range of pressures, the rate of pressure change (which maybe indicative of an occlusion) may be determined without actual pressuredeterminations.

Referring now to FIGS. 41 and 42, the exemplary pressure sensor 234includes the cartridge portion 120 a, which is associated withmedicament cartridge 100 a described in Section III above, and the pumpassembly portion 236. The cartridge portion 120 a may include, amongother things, a detectable structure 124 a with a magnet 132 a that iscarried by a resilient diaphragm 134 a. The diaphragm 134 a, which isexposed to reservoir pressure by way of the aperture 128, flexes inresponse to pressure increases, thereby resulting in movement of themagnet 132 a. The pump assembly portion 236, whose location is fixedrelative to the medicament cartridge 100 a, may be a sensor thatresponds to changes in the adjacent magnetic field (e.g., a Hall-effectsensor or a magnetoresistive sensor). As the magnet 132 a moves relativeto the pump assembly portion 236, the sensor responds to the associatedchanges in the adjacent magnetic field (e.g., with a change in outputvoltage or a change in resistivity). The pump assembly portion 236 isoperably connected to the controller 240, and the controller may beconfigured to equate sensor responses to changes in pressure within thethrough-bore 116. To that end, the pump assembly portion 236 can bemounted on the circuit board associated with the controller and/or maybe thought of as the powered part of the sensor.

With respect to operation of the pressure sensor 234, it shouldinitially be noted that a fluid delivery procedure would be performedwith, for example, a cannula connector plug (e.g., plug 602 in FIG. 57)or a connector plug 550 for an infusion set (FIG. 63) located within thecartridge through-bore 116. Such structures have been omitted from FIGS.41 and 42 to simplify the illustrations. The detectable structure 124 ais shown in the “at rest” position in FIG. 41, which may correspond tolittle or no pressure within the cartridge through-bore 116. Thedistance between the magnet 132 a and the pump assembly portion 236 isD1. As pressure within the cartridge through-bore 116 increases,deflection of the diaphragm 134 a results in the distance between themagnet 132 a and the pump assembly portion 236 decreasing, and theassociated sensor will respond accordingly. A pressure change associatedwith the missed delivery of six μl of medicament (e.g., 5 psi), whichmay be considered to be the result of an occlusion, will decrease thedistance between the magnet 132 a and the pump assembly portion 236 byan amount ΔD to D2 in the illustrated embodiment.

The discussion here is, of course, equally applicable to the exemplarymedicament cartridge 100 (with cartridge portion 120 a) described inSection III. Also, as discussed above in the context of FIGS. 3-8, otherexemplary detectable structure arrangements include, but are not limitedto, a magnetically permeable structure carried on a diaphragm andmovable relative to a coil; and an optical element carried on adiaphragm and movable relative to an optical sensor; and an electricalconductor carried on a diaphragm and movable relative to a pair ofswitch contacts. It should also be noted that, with respect to theimplementations that include a pressure sensor, the present inventionsare not limited to pressure sensor arrangements that include adiaphragm, or to pressure sensor arrangements that include a cartridgeportion and a pump assembly portion. For example, a medicament cartridgemay include a pressure sensor that communicates with the pump assemblyby way of electrical contacts.

Given the very short distance that the magnet or other detectablestructure travels (e.g., ΔD=about 0.1 to 1 mm), changes in the locationof the medicament cartridge (e.g., cartridge 100 or 100 a) relative tothe pump assembly portion 236 of the sensor 234 may adversely effect theaccuracy of the measurements. Accordingly, in at least someimplementations, various structures are provided to position and holdthe medicament cartridge at a predetermined location within thecartridge receiving area 220, e.g., the spring bias clips 268 and thelatches 412 and 412 a described above with reference to FIGS. 18, 23-26and 32-35A. It should also be noted here that the above-described “lowsystem compliance” aspect of the present pump assemblies contributes tothe accuracy of the sensor measurements by maintaining the intendedspatial relationships between the sensor components, such as pressuresensor cartridge portion 120 a, pump assembly portion 236, and thewindow 287 therebetween (FIG. 41).

I. Exemplary Fall-Off Detectors

The present inventors have determined that one issue associated with anypatch pump is that it may be fully or partially dislodged from thepatient's skin (i.e., “falls off”) without the patient's knowledge. Suchfull or partial dislodgement could bend the cannula or otherwiseinterfere with medicament delivery.

A variety of mechanisms that detect when a patch pump has beendislodged, and provide an appropriate signal to the system controller(e.g., controller 240), are discussed below with reference to FIGS.43-47. The system controller may take various steps, e.g., activation ofan alarm and/or stopping of the motor, in response to a fall-off signal.Although not limited to use with any particular type of patch pump, thedetection mechanisms are described below in the context of patch pumpsystems that are otherwise identical to the above-described system 10(FIGS. 1 and 54) to simplify the explanation. Similar elements arerepresented by similar reference numerals. Other exemplaryimplementations include, but are not limited to, patch pumps that do notinclude a baseplate.

As illustrated for example in FIGS. 43 and 44, an exemplary pumpassembly 200 a is provided with a switch-type detector 650 within thehousing 202 a, and the exemplary baseplate 500 a is provided with adetector aperture 505 that extends through the plate member 506. Theexemplary detector 650 may include a switch 652 and a movable switchactuator 654. The switch 652 may be a self-contained structure that isbiased to the open state (FIG. 43) and that closes in response tocontact with the switch actuator (FIG. 44). In other implementations,some or all of the switch may be carried by the associated switchactuator. The switch actuator 654, which is biased to an extendedposition (FIG. 44) by a spring 656 or other bias device, may include anabutment 658 that rests on the skin surface S when the baseplate 500 ais secured to the skin and the pump assembly 200 a is secured to thebaseplate (FIG. 43). A detector aperture 205 is provided on the housing202 a to permit movement of the switch actuator 654. The abutment 658 iscarried on one end of a post 660, and a stop 662 is carried on the otherend. The stop 662 both limits travel of the switch actuator 654 andengages the switch 652 during a “fall-off.”

So configured, the actuator 654 will be out of contact with the switch652 when the baseplate 500 a is secured to the skin and the pumpassembly 200 a is secured to the baseplate (FIG. 43). As the baseplate500 a separates from the skin surface S due to failure of the adhesive542 (FIG. 44) or a pulling force on the baseplate or pump assembly, orthe pump assembly 200 a separates from the baseplate due to failure ofthe connection therebetween, the biasing force of the spring 656 willmove the stop 662 toward the switch 652 until contact is made, theswitch is closed, and a signal is sent to the controller.

The exemplary switch-type detector 650 may be calibrated, by adjustingthe distance D that the switch actuator 654 must travel prior to closingthe switch 656, to define the magnitude of the separation that willtrigger a signal to the controller 240 and, in at least some instances,a subsequent patient alert. In the illustrated implementation, thedistance D may about 0.5 to 2.0 mm.

Another exemplary fall-off detector arrangement is generally representedby reference numeral 650 a in FIG. 45. The exemplary detector 650 aincludes a sensor 664, which is carried within or by the housing 202 bof a pump assembly 200 b, and a movable sensed structure 666 that iscarried by the baseplate 500 b. The type of sensor will depend upon thetype of structure being sensed. In the exemplary implementation, thesensed structure includes a magnet 668 and, accordingly, the sensor 664is a sensor that is configured to sense changes in magnetic fields suchas, for example, a Hall-effect sensor or magnetoresistive sensor. Thehousing 202 b also includes an indentation 207 to accommodate the sensedstructure 666.

The manner in which the magnet 668 (or other sensed structure) iscarried on the baseplate may vary. As illustrated for example in FIG.45, the magnet 668 is carried on a post 670 that extends through adetector aperture 505 in the plate member 506. A seal 672 may be carriedon the post 670. A steel disk 674 is carried by the plate member 506.Elastomeric sheets 676 and 678 may be secured to the plate member 506 toenclose the magnet 668, post 670 and steel disk 674.

So configured, the sensed structure 666 will be relatively close to thesensor 664 when the baseplate 500 b is secured to the skin and the pumpassembly 200 b is secured to the baseplate (not shown). As the baseplate500 b and attached pump assembly 200 b separate from the skin surface Sdue to failure of the baseplate adhesive (not shown), the magneticattraction between the magnet 668 and steel disk 674 will pull themagnet away from the sensor 664. When the distance therebetweenincreases to distance D, the magnitude of the change in the magneticfield experienced by the sensor 664 will be such that a signal is sentto the controller. The sensor 664 will experience a similar change inthe adjacent magnetic field should the pump assembly 200 b separate fromthe baseplate 500 b due to failure of the connection therebetween.

The exemplary sensor-type detector 650 a may be calibrated by adjustingthe distance D that the appropriate portion of the sensed structure 666(e.g., magnet 668) must travel prior to a signal to the controller beingtriggered and, in at least some instances, a patient alert beingprovided. In the illustrated implementation, the distance D may be about0.5 to 2.0 mm.

Another exemplary detector, which is generally represented by referencenumeral 650 b in FIG. 46, is in the form of an RF circuit with atransmitting antenna 680, a receiving antenna 682, and an RF energysource 684. The RF energy source may be powered by the system battery238. The receiving antenna 682 is positioned relative to thetransmitting antenna 680 such that the amplitude of the RF fieldreceived changes as the baseplate becomes separated from the user's skinsurface S, as shown by waveforms A1 and A2. For example, A1 may be abouttwice A2. The received RF field has a greater amplitude against skinthan in air. In response to a decrease in amplitude, the RF circuitsends a signal to the controller. The transmitting antenna 680 can bemounted in either one of the baseplate and the pump assembly (notshown), the receiving antenna 682 can mounted in either one of thebaseplate and the pump assembly, and transmitting antenna and thereceiving antenna can both be embedded in the baseplate 500 c (asshown). In those instances where the RF energy source is carried by thebaseplate, power may be provided by way of the pump assembly electricalcontacts 228 and 230 (FIG. 16) and the baseplate contacts 228BP and 230BP (FIG. 66)

Another exemplary detector, which is generally represented by referencenumeral 650 c in FIG. 47, is in the form of an electrical circuit havinga first electrical terminal 686 and a second electrical terminal 688,spaced from the first terminal, and carried on baseplate 500 c′. Theelectrical circuit is completed between the first and second terminals686 and 688 by the user's skin when the associated baseplate 500 c′ isadhered to the skin surface S by the baseplate adhesive, and is brokenwhen the baseplate becomes separated from the skin. A signal is sent tothe controller when the circuit is broken. In the illustratedembodiment, the first and second terminals 686, 688 may be in the formof electrically conductive pads carried on the bottom surface of thebaseplate 500 c′. The “fall-off” signal may be a voltage signal and theexemplary circuit is configured to convert current of the electricalcircuit to the voltage signal.

J. Exemplary Batteries and Battery Rechargers

The battery that drives the motor may be a rechargeable battery, such asa rechargeable lithium polymer battery or a rechargeable lithium ionbattery. At least some implementations will employ a rechargeablebattery having a fully charged, open circuit voltage of generally 4.2Volts, or 4.18-4.24 Volts. One advantage of lithium polymer and lithiumion batteries is that they can be recharged quickly by the patient, havehigh energy density, and have desirable linear decay that facilitatesaccurate charge state indication. Turning to FIG. 49, the exemplarybattery 238 may be carried within the pump assembly housing 202 in acompartment that is separate from the cartridge compartment 246.Additionally, because the battery 238 is rechargeable and the housingincludes external recharging contacts 228 and 230, the exemplary housing202 does not include a door or a cover to provided access to thebattery, and the exemplary housing may be sealed (i.e., it cannot beopened without damage thereto).

In at least some instances, the user may seek to recharge the battery238 when there is medicament in the cartridge 100. Note that thecartridge 100 will be locked into the pump assembly 200 so long as theplunger pusher 250 is not in the fully retracted position, as isdiscussed above with reference to, for example, FIGS. 23-26. So locked,the cartridge 100 and pump assembly 200 will separate from the “patchpump” baseplate 500 and cannula 600 in the manner illustrated in FIG.48, while the baseplate and cannula remain on the skin surface S of theuser, when the user pulls the pump assembly off of the baseplate.Similar separation will occur in the context of an “infusion set”baseplate 501 and a “non-delivery” baseplate 502 (FIG. 1).

Given the relatively close proximity of the battery 238 to themedicament cartridge 100, heat from the battery 238 could possiblyincrease the temperature of the medicament during recharging, especiallyduring rapid recharging. The medicament temperature may be relevant tocertain medicaments such as insulin, for example, which can be damagedand have its viability become undefined at about 37° C. Accordingly, atemperature sensor 239 (e.g., a thermistor or thermocouple) may also becarried within the pump assembly housing 202 in such a manner that thetemperature sensor can sense the temperature of the medicament in thecartridge 100 (or a temperature that is at least representativethereof). For example, the temperature sensor 239 may be carried on thecircuit board associated with the exemplary controller 240 (FIG. 18) oron the chassis 244 (FIG. 18). Temperature sensing apparatus, such as aheat pipe that extends to the reservoir (not shown), may also beincluded on some cartridge implementations. The temperature informationmay be provided to the controller 240, or to another controller, tomodulate the battery recharging process as a function of temperature asis described below.

One example of a battery recharger, which is generally represented byreference numeral 700 in FIG. 49, includes recharging circuitry 702(e.g., a controller and power circuitry) within a housing 704. The topportion of the recharger housing 704 may be configured in a mannersimilar to the baseplate 500. To that end, the top portion of thehousing 704 may include a plate 706, a cartridge recess 708, a pair ofopposing connectors 712, a hook 714, and electrical contacts 228R and230R. In some implementations, a temperature sensor 739 may be providedat or near the recess 708 to sense the temperature of medicament in thecartridge 100 during recharging. Power and data connectors 716 and 718may also be provided.

The respective configurations of the pump assembly 200 and batteryrecharger 700 are such that, when the pump assembly is placed on theplate 706 with an end wall 212 abutting the hook 714, the pump assemblyrecharge contacts 228 and 230 will be electrically connected to therecharger contacts 228R and 230R. Also, when the cartridge 100 is withinthe pump assembly 200 during the recharging procedure, the cartridgebarrel 102 will nest in the recess 708 to insure proper alignment of theelectrical contacts 228/230 and 228R/230R. The recess 708 may also beconfigured to accommodate the finger tab 456 associated with the latch412 a (FIG. 32).

The recharging process may be controlled by circuitry 237 associatedwith the pump assembly controller 240, the recharger controller 702,separate circuitry, or some combination thereof, which are collectivelyreferred to as the “recharge controller.” The recharge controller 702may modulate the recharging of the battery 238 as a function of thetemperature sensed by temperature sensor 239 and/or temperature sensor739. For example, and weighing the desire to rapidly recharge thebattery 238 against the desire to avoid medicament damage, the rechargecontroller may be configured to maintain the sensed temperature within atemperature range that is above a predetermined threshold and below apredetermined maximum for the particular medicament. In the exemplarycontext of insulin and a lithium polymer battery, the thresholdtemperature can be 37° C. (or range from, for example, 36.6-37.4° C.)and the predetermined maximum temperature can range from, for example,45-50° C.

It should also be noted that it may be difficult for the battery 238 toprovide enough current if the temperature within the pump housing 202 islow. The temperature sensor 239 may, therefore, be used to monitortemperature during operation of the pump assembly 200. An alarm may beactuated by the controller 240 if the temperature is too low.

Modulation of the recharging process may be accomplished by, forexample, selectively increasing or decreasing the rate at which thebattery 238 is recharged (e.g., by controlling current) as a function ofsensed temperature. For example, and referring to FIG. 50, themodulation process may be designed to perform temperature control in amanner that prevents the sensed temperature from overshooting thepredetermined maximum temperature (T_(MAX)) as shown by the dashedlines. To that end, as temperature reaches a modulation temperature(T_(MOD)) below the maximum temperature T_(MAX), the recharging rate isreduced to keep the temperature at or below the maximum temperatureT_(MAX).

In at least some implementations, the charge controller may beconfigured to identify and/or prevent charging faults, such as batteryovercharge that can cause the battery to swell, vent and otherwisestress other components within the pump assembly.

It should be noted here that the present pump assemblies and batteryrechargers are not limited to those which make a direct electricalconnection through the use of electrical contacts. By way of example,but not limitation, inductive coupling may be employed. It should alsobe noted here that at least some implementations of the present pumpassemblies may be configured to accept a replaceable battery. Suchimplementations would, however, require a waterproof battery compartmentcover.

K. Exemplary Alarms

As noted above with reference to FIG. 18, the exemplary pump assembly200 may include an alarm 242 that is carried within the housing 202. Thealarm may be audible (e.g., a buzzer), palpable (e.g., a vibrator),visible (e.g., an LED with a portion that extends through the housing202) and/or any combination thereof. A number of conditions may resultin alarm activation in the exemplary embodiments. For example, asdiscussed in Section IX below, alarm conditions include, but are notlimited to, low or dead battery, occlusion, low or empty reservoir,hardware self-test, firmware error, absence of a baseplate, devicefall-off, battery charge over-temperature, unable to find plunger,and/or charging faults.

L. Exemplary System Controllers

The exemplary pump assemblies described herein may include a controllerthat is configured to perform the various control functions describedherein. The controller may also operate/execute algorithms for periodicsafety checks such as memory checksums, hardware verification selftests, and the like. The present inventions are not limited to anyparticular type of controller and include those currently available oryet to be developed. By way of example, but not limitation, such acontroller may be in the form of a microcontroller and stored firmwareprograms. The microcontroller may include, among other things, some orall of a microprocessor or other central processing unit (CPU), otherdigital and/or analog control circuitry, digital and/or analogcommunication circuitry, and memory such as static random access memory(SRAM), flash memory, and synchronous dynamic random access memory(SDRAM). The controller may employ any suitable control principlesincluding, but not limited to, proportional, adaptive, neural network,fuzzy logic, and/or proportional integral derivative (PID). Themicrocontroller may also support firmware updates through an RFinterface.

One exemplary controller is generally represented by reference numeral240 in FIG. 18 and is described here, in the context of various systemcomponents that are connected thereto, with reference to FIG. 51. Theexemplary controller 240 may include a microcontroller (labeled μ-C inFIG. 51) with a CPU, flash memory, SRAM, and a built-in RF transceiver.Building the RF circuitry into the controller decreases the size of thecontroller by positioning everything on a single chip. One example of asuitable microcontroller is the Texas Instruments CC2530microcontroller.

A pair of oscillator crystals 249 respectively provide clock sources forthe RF transceiver and the microcontroller. A filter capacitor for themicrocontroller power supply is shown at 247.

As discussed above and below, a variety of devices may be operablyconnected to the controller 240. Referring to FIG. 51, such devices mayinclude the position detector 398 (FIG. 29) that detects when theplunger pusher 250 is in the fully retracted (or “home”) position, thesensor(s) from an encoder that monitor motor shaft rotation (e.g.,sensors 403 a and 403 b of encoder 396 j), and the temperature sensor239, which may be a thermistor, creates a variable analog voltage whichconnects to an analog ADC input.

With respect to power, the recharging contacts 228, 230 connect thebattery 238 to the battery recharger 700 (FIG. 49). The charging voltageis distributed by a distribution circuit 243 to the battery 238 and to avoltage regulator 231. A protection circuit 241 is provided for thebattery 238, and a regulator 231 regulates the power delivered to themicrocontroller. The recharger controller 237, if present, may be usedto control recharging of the battery 238 in those instances where thebattery recharger 700 does not perform this function. A voltage divider245 reduces the voltage to be compatible with the analog input of themicrocontroller and allows the microcontroller to read the full range ofthe output of the battery 238. To conserve battery power, the divider245 is only enabled when battery voltage is being sensed. When thedivider 245 is enabled, the voltage at the associated pin isBatteryVoltage*Rb/(Ra+Rb). Thus, the voltage is a fractionalrepresentation of the actual battery voltage so that the input range ofthe pin is not exceeded. The analog-to-digital converter input sensesthis voltage. The microcontroller's built-in analog-to-digital converterconverts the voltage to a digital value (e.g., a 10 bit digital value).

In those implementations where a switch-type fall-off detector isemployed (e.g., detector 650 in FIGS. 43 and 44), the input to R4 is adigital input that senses the actuation of associated switch S3. Thisinput allows the microcontroller to sense the position of the portion ofthe detector that protrudes through the housing 202 (e.g. abutment 658)and can be programmed to wake the microcontroller up from an extremelylow power state.

The alarm 242, which may be audible, palpable and/or visible, has adriver circuit to increase the current drive to it. A mute switch 1004may also be provided, e.g., on the pump assembly housing 202, to mute anaudible alarm.

A sending and receiving antenna 1002 is provided to communicate with,for example, the remote control 1000. An impedance matching circuit 1003for the antenna 1002 receives its power from the transceiver.

M. Exemplary Motor Control

Turning to motor control, and referring to FIG. 51, the motor 358 (e.g.,a stepper motor) actuated by the phases of the motor coils C1, C2. Thephases are energized in the proper sequence to drive the motor 358 atthe desired speed and in the desired direction. The interlock circuit361 is a simple missing pulse detector which can be implemented with are-triggerable monostable multivibrator integrated circuit such as a74HC123 CMOS device from NXP Semiconductors. The interlock circuit 361is enabled by a pin 365 that continuously toggles from high to low, andsoftware of the microcontroller causes the pin to toggle. Thus, if thesoftware stops functioning, the pin will not toggle and the motor 358will be automatically disabled for safety reasons by the interlockcircuit 361. More particularly, output 365 enables the motor interlockcircuit 361, protecting against over-delivery of medicament due to asoftware lockup.

Pulse width modulating (PWM) circuit 363 is the motor enable output thatenables the drivers DR1, DR2 to the motor 358. Put another way, the PWMcircuit 363 modulates energy from the battery 238 applied to motor coilsC1, C2. This pulse width modulated output enables control of the motorcurrent depending on the programmed torque and the voltage of thebattery 238. Circuit 363 operates at a frequency ten to one hundredtimes higher than the motor phases, and avoids having to use a regulatorfor the motor voltage.

Drivers DR1, DR2 energize the coils C1, C2 of the motor 358 and changetheir polarities. Assuming the interlock circuit 361 has been enabledand output F is at a logic 1, driver DR1 is enabled with positive driveto coil C1 when output C is a logic 1 and A is a logic 0. Likewisedriver DR2 is enabled with positive drive to coil C2 when output B is alogic 1 and D is a logic 0. Under the same conditions, driver DR1 isenabled with negative drive to coil C1 when output C is a logic 0 and Ais a logic 1. Likewise driver DR2 is enabled with negative drive to coilC2 when output B is a logic 0 and D is a logic 1. If A=C, driver DR1 isdisabled. Similarly if B=D, driver DR2 is disabled. If output F is alogic 0 or if the interlock circuit 361 is disabled, both drivers aredisabled regardless of the state of outputs A-D. The pulse widthmodulation occurs when output F of PWM circuit 363 pulses at a givenduty cycle. If F pulses at a 75% duty cycle, then the coils will beturned on with the polarity as selected by A-D, with an effectivevoltage of 75% of the battery voltage.

FIG. 51A is a block diagram that illustrates the functionalrelationships of certain elements/components shown in FIG. 51 and, inparticular, the relationship of the battery charging system to the othercomponents of the system. The battery charging system, as shown in thelower left in a dotted line block, includes the battery 238, the batteryprotection circuit 241, the power connectors 228, 230 and the chargecircuit 237. As can be seen in FIG. 51A, one way the battery chargingsystem connects to the microcontroller is through the voltage divider245. The motor drivers DR1, DR2 receive power from the battery and drivethe motor 358 whose position is sensed by the position sense encoder 396j. The interlock circuit 361 provides a safety shutoff of the motordrivers DR1, DR2 when there is a software problem in themicrocontroller. Oscillator crystals 249 provide clocking functions forthe microcontroller and RF transceiver. The microcontroller controls theoperation of the alarm 242. The antenna 1002 is connected to themicrocontroller by way of the antenna circuit 1003.

Energy to the motor 358 may be controlled so as to be within a rangehaving a lower limit that provides sufficient torque to overcome driveline inefficiencies and axial cartridge friction and move the plunger106, and an upper limit that is low enough so as to not cause leakagepast plunger seals 152. FIG. 52 is a flow chart showing an exemplary lowtorque motor control procedure. Referring thereto, a firmware counterwith the number of encoder counts required to advance the pusher adistance corresponding to the desired drug dose is loaded in thecontroller 240 (Step S001). The motor 358 is excited (Step S002) and theencoder 396 is monitored (Step S003). If no motor rotation is detected(Step S004), then the excitation current is up-regulated to increase themotor torque (Step S005) and the process is returned to thepreviously-mentioned motor excitation step (Step S002). On the otherhand, if motor rotation is detected, the counter is decremented (StepS006).

If the counter is not zero (Step S007), then the excitation current isdown-regulated to limit the motor torque and to conserve energy (StepS008), and the process is returned to the previously-mentioned motorexcitation step (Step S002). If the counter is zero (Step S007), thenmotor excitation is continued for additional motor steps past thefirmware count zero for subsequent detection of motor rotation followingcessation of motor excitation (Step S009). Following completion of theadditional motor steps, delivery is thereby at an end (Step S010).

The excitation current regulation method mentioned in the up-regulateand down-regulate steps above varies with the method used. Examples ofmethods are (a) pulse width modulation and (b) a programmable linear orswitching type voltage regulator. Up and down regulation using a voltageregulator increases or reduces the voltage output to the coil drivers.For a pulse width modulation method, down regulation reduces the dutycycle and up regulation increases the duty cycle.

In other words, pulse width modulation is one way to control energyconsumption and provide a prescribed (e.g., 10 pound) stall limit. Astall limit that is too low will not provide sufficient performanceagainst drive line and cartridge inefficiencies, while a stall limitthat is too high can overdrive the cartridge and, potentially, createexcessive reservoir pressure that will cause leakage past the cartridgeseals 152 during a pusher “zeroing” procedure (described in SectionVIII-B with reference to FIG. 91) or during an occlusive event(described in Section VIII-C with reference to FIGS. 92 and 93).

Pursuant to an exemplary embodiment the motor 358 always runs underpulse width modulation or other torque control method, as the motor isdesigned with excess torque that needs to be controlled. Pulse widthmodulation is one effective method to control the torque. The electronicdrive provided for the motor is important to minimize battery drain aswell as to control the torque the motor is providing to the system andwhat forces the lead screw 360 is putting on the cartridge 100 in allcases, e.g., retracting, homing, zeroing, running, and occlusiondetecting.

Referring to FIG. 52A, one of the drivers DR1, DR2 in FIG. 51 is shownconnected to the associated motor winding. Rs is a current sensingresistor (about 1Ω) for implementations that directly sense the coilcurrent, and Vs is the current sensing voltage. The inductor (L) is theinductance of the motor winding and the load (R) is the windingresistance. The switch 359 c is a FET driver, and diodes 359 a and 359 bare intrinsic back-diodes within the FET drivers. These componentsessentially form the elements of a basic buck-type switching regulator,with R being the load. When the ENABLE bar shown in that figure (and inFIG. 51) is a logic 0 (the true condition), the switch 359 c turns onand power is thereby provided to the rest of the circuit, therebyenabling the coil drivers. If the switch 359 c is turned on and off at arate faster than R/L, then the voltage to the load R will be effectivelyreduced in the manner of a buck-type switching regulator. During the ontime of switch 359 c, inductor L charges by ramping up its current,thereby limiting the voltage applied to load R. During the off time ofswitch 359 c, the inductor L discharges by ramping down its current,thereby continuing to supply voltage to load R. Inductor L dischargesthrough the load R and the intrinsic back-diodes 359 a and 359 b. Thiscircuit could be further enhanced by adding Schottky diodes across theintrinsic back-diodes 359 a and 359 b to reduce the voltage drop whenthe inductor L discharges through them during the off time of switch 359c. This is much in the same manner that Schottky diodes are found inbuck-type switching regulators.

The equation to be relied on is: Veff=D*Vbatt, where Veff is theeffective voltage to the coil resistance R, D is the pulse-widthmodulation duty cycle, and Vbatt is the battery voltage. If the battery238 is fully charged to 4.0 volts and the motor 358 is to be run asthough the battery voltage were only 3.0 volts, pulse-width modulationis done at a 75% duty cycle. The effective voltage to the coilresistance R is 0.75 *4.0=3.0 volts. As the battery voltage drops to 3.0volts the duty cycle will be increased to 100% and no switching willtake place. The frequency of the switching will be determined by the L/Rtime constant. For an exemplary motor L=3.5 mH and R=30 Ohm, so L/R=117μSec. The frequency has a period less than the time constant to insure arelatively linear ramp-up and down of the inductor current. This ensuresthat the equation Veff=D*Vbatt holds true. This method can be used tofurther reduce the effective voltage to the coil resistance if desired.This can be done to limit the pressure within the reservoir. A filtercapacitor across the load R used in a traditional buck type switchingregulator is not necessary due to conservation of energy. It simplyholds charge to reduce voltage ripple, while the motor actually operateson electrical current, not voltage. In the description above, the coilcurrent is directly proportional to the effective voltage Veff, sincethis voltage is considered to be across the purely resistive portion Rof the coil load. Thus, for example, if the effective voltage to R isreduced by 25%, the current will also be reduced by 25%.

The pulse width modulation system may include an analog-to-digital (ND)converter which converts voltage of the battery to a digitalrepresentation. The controller (a) operates through a driver circuit tocontrol the operation of the motor and to pulse-width modulate energyfrom the battery applied to coils of the motor, (b) reads the digitaloutput of the encoder and (c) reads the digital output of the NDconverter.

The controller 240 may include a first software algorithm adapted to usethe digital representation of the motor position to program a firstdigital timer/counter circuit in the controller to provide low levelsignal outputs that enable the drivers DR1, DR2 of the motor 358 tofacilitate a sequencing of voltage at the coils C1, C2 of the motor toproduce a desired motor rotation. The controller 240 may also include asecond software algorithm that uses the output of the A/D converter toprogram a second digital timer/counter circuit in the controller toprovide a low level signal output that further enables the drivers DR1,DR2 of the motor 358 to facilitate the pulse-width modulation of thevoltage to the coils C1, C2 of the motor 358.

The steps of the first software algorithm may be as follows: (1)determine the position of the motor shaft by reading the encoder 396;(2) determine the direction of rotation (either forward/delivery orreverse/retraction); (3) determine the number of rotations required (howmuch drug delivery or how far to retract); (4) step the motor 358according to the sequence defined by the motor manufacturer'sspecification by driving coil phase A and B either+ or −; and (5) repeatstep (4) at a rate, which is determined by analysis and characterizationduring development, that guarantees movement with normal loads until thedesired number of rotations is read from the encoder 396. Steps (4) and(5) may be performed by the first digital timer/counter circuit wherethe outputs are connected to the drivers DR1, DR2 for the motor coilsC1, C2 while the microcontroller is reading the outputs of the encoder396.

The steps of the second software algorithm may be as follows: (1)determine the effective motor coil voltage (Veff) required (for example,2.7 volts to run the motor 358 in the forward direction, 1.1 volts torun the motor in the reverse direction; the actual voltages will bedetermined after analysis and characterization during development); (2)read the ND converter output containing the digital representation ofthe battery voltage (Vbatt); (3) calculate Veff/Vbatt; and (4) programthe second digital counter/timer circuit to output a digital pulsewaveform with a duty cycle of Veff/Vbatt at a frequency of 10 to 100times the rate of step (5) of the first software algorithm. The outputof the second digital timer circuit will be a global enabling signal forboth motor coil drivers DR1, DR2.

Thus, even though the circuit determines, for example, that at aparticular time, coil phase A should be driven at +Vbatt and coil phaseB should be driven at −Vbatt, the output of the second timer is thegating signal that determines when the drivers are actually enabled todrive the selected levels to the coils. The result will be that coilphase A will be driven at +Vbatt, but on and off at a duty cycle ofVeff/Vbatt and likewise for coil phase B. This on and off rate will bemuch higher than the rate that the drivers DR1, DR2 will switch thepolarity of the coil phases to perform the specified sequencing thatcauses the motor 358 to rotate. The effect is to limit the current toVeff/Vbatt times the amount of current that would be used if the fullbattery voltage were applied to the coils 100% of the rotation time.

Thus, torque can be limited by limiting the current to the motor coilsC1, C2. Other ways to limit the current are to use a constant currentsource. However, this can be somewhat complex and wasteful of batteryenergy. A constant voltage source can be used. Since the coil resistancelimits the current, limiting the voltage will effectively limit thecurrent. This can be done in either of two ways. A linear voltageregulator may be employed, although this may be an unnecessary drain onthe battery. Alternatively, a switching voltage regulator may beemployed, which is more efficient in that it uses a coil to storeenergy, but includes more parts.

V. Exemplary Baseplates and Cannulas

As noted above, and as illustrated for example in FIG. 1, the presentinfusion systems may include any one of a variety of differentbaseplates in combination with a cartridge (e.g., cartridge 100) and apump assembly (e.g., pump assembly 200). Each baseplate may beconfigured for a different mode of system operation. Baseplate 500 is abody adherable baseplate that may be used in conjunction with a cannulasuch as cannula 600 (FIGS. 56-57) which is directly connected to thecartridge 100 so that the system may be deployed as a “patch pump.”Baseplate 501 is configured to connect the cartridge 100 to an infusionset 503 so that the system may be deployed as a “pocket pump,” a“belt-worn pump” or some other wearable pump. Baseplate 502 is amedicament non-delivery baseplate that includes a plug 504 which may beused to seal the cartridge 100 during periods of non-use. Additionally,and as discussed in Section VI below, pump assemblies (e.g., pumpassembly 200) and baseplates (e.g., baseplates 500-502) may berespectively configured such that a pump assembly can determine whichone of a variety of baseplates is attached to the pump assembly and thenprepare to proceed in accordance with the operational mode associatedwith that baseplate. Also, although the exemplary baseplates aredescribed herein in the context of the exemplary cartridge 100 and theexemplary pump assembly 200, the present baseplates may be used inconjunction with other cartridges, cartridge-based pumps, and pumps thatare not cartridge-based.

Turning to FIGS. 53-55, the exemplary body adherable baseplate 500 mayinclude a plate member 506 that is configured to cover the insertionopening 218 (FIG. 16) in the housing bottom portion 208. A cartridgeaperture 508 (or simply a recess) may be provided to accommodate amedicament cartridge such as cartridge 100, or may be omitted, and acannula aperture 510 may be provided to permit passage of a cannula inthose instances where the plate member 506 would otherwise block thecannula. It should also be noted that the cartridge 100, pump assembly200 and baseplate 500 are respectively configured such that a portion ofthe cartridge manifold 108 will rest on the plate member 506.

The exemplary baseplate 500 also includes structure that perform thefunction of securing the baseplate to the associated pump assembly. Forexample, in the embodiment illustrated in FIGS. 53-55, the baseplate 500includes a pair of opposing connectors 512 and a hook 514. Theconnectors 512 frictionally engage the side walls 210 of the pumpassembly housing 202, and may have an engagement portion 516, a supportportion 518 that connects the engagement portion to the plate member506, and a protrusion 520 to engage the user's finger. Gaps 522, whichare located on either side of the support portion 518, allow the supportportion to pivot in the direction shown by arrow P. The distance betweenthe engagement portions 516 is less than the distance between the outersurfaces of housing side walls 210 when the connectors are in anunstressed state. As such, when the housing 202 and baseplate 500 arepressed together (FIGS. 54-55), thereby pivoting the connectors 512 outof their unstressed states, the engagement portions will apply forces Fto the housing side walls 210 that are sufficient to provide enoughfrictional engagement to prevent separation during normal usage. Thehook 514 may include an engagement portion 526 and a support portion524, and gaps 528 may be located on either side of the support portion524 if hook flexibility is desired.

During attachment of the baseplate 500 to the pump assembly 200, abottom corner of the housing end wall 212 may be aligned with the space528 defined by the hook 514. The baseplate 500 and pump assembly 200 arethen moved relative to one another (e.g., pivoted about the hook 214) tothe position illustrated in FIGS. 54-55, where the connectors 512frictionally engage the housing side walls 210 and secure the baseplateto the pump assembly.

In at least some embodiments, the baseplate and associated cannula maybe configured to secure themselves to one another. As a result, the pumpassembly (e.g., pump assembly 100) and medicament cartridge (e.g.,cartridge 200) may be removed together as unit from the baseplate withthe cannula remaining secured to the baseplate as noted above withreference to FIG. 31. This allows, for example, the pump assemblybattery to be recharged without removing the cartridge. The user mayalso use this capability to remove the baseplate and cannula fromhis/her body and then redeploy the system with a new baseplate andcannula at a different location.

One exemplary baseplate and cannula configuration is illustrated inFIGS. 55A-57. The exemplary baseplate 500″ is essentially identical tobaseplate 500 and similar elements are represented by similar referencenumerals. In addition, a recess 511 with a mating surface 513 ispositioned around the cannula aperture 510 on the bottom side (i.e.,adhesive side) of the plate member 506. The recess 511 is used to securea cannula to the baseplate 500″ in the manner described below.

The exemplary cannula 600 is configured to establish a fluidicconnection between a medicament cartridge (e.g., cartridge 100) and thepatient. The exemplary cannula 600 is also configured to cooperate withthe recess 511 such that axial movement of the cannula relative to thebaseplate 501 is prevented, at least in the removal direction, after thecannula has been deployed into the patient.

With respect to the fluidic connection, the cannula 600 may include aconnector plug 602 (or “head”) that is configured to be inserted intothe cartridge through-bore 116. The exemplary connector plug 602 mayinclude a cylindrical member 604 with an internal lumen 606, at leastone inlet port 608 connected to the internal lumen, o-ring or otherseals 610 on opposite sides of the inlet port(s) 608. A cannula tube 612may be connected to the connector plug 602. The exemplary seals 610 maybe integral with the cylindrical member 604, or may be separatestructures formed from rubber or other appropriate seal materials thatare carried thereon.

Turning to cooperation with the baseplate recess 511, the exemplarycannula 600 includes a latch (or “hook”) 614. Although the latch may beany suitable configuration, the exemplary latch 614 is a resilientstructure that includes a latch surface 616 and a frustoconical support618 below the latch surface. The latch 614 will deflect as the cannula600 is deployed through the medicament cartridge through-bore 116 in themanner described above with reference to FIGS. 45-49. Here, the insertertrocar (e.g., trocar 812 in FIG. 85) will push through the top of thecylindrical member 604, through the internal lumen 606, and through thecannula tube 612, while the inserter drive structure (e.g., movablemember 802 in FIG. 85) pushes the top of the cylindrical member. Oncethe resilient latch 614 passes through the cannula aperture 510, it willreturn to its relaxed state and the latch surface 616 will abut themating surface 513 in the baseplate recess 511 (FIG. 57). Thefrustoconical support 618 will then prevent the cannula 600 from beingpulled back through the cannula aperture 510.

It should also be noted that the respective sizes (e.g., diameters) ofthe recess 511 and the latch surface 616 are essentially the same. Thisrelationship produces a tight fit that helps prevent lateral movement ofthe baseplate 500″ relative to the cannula 600.

It should also be noted that the configuration of the associatedinserter, e.g., inserter 800 in FIG. 85, prevents downward movement ofthe cannula 600 beyond that illustrated in FIG. 57. In otherimplementations, a cannula and/or baseplate may be provided withstructure that performs this function.

The exemplary cannula 600 a illustrated in FIGS. 58 and 59 isessentially identical to cannula 600 and similar elements arerepresented by similar reference numerals. In addition, cannula 600 aincludes a septum 620. The septum 620, which is formed from softermaterial than the cylindrical member 604, facilitates smooth passage ofan inserter trocar to the internal lumen 606.

The dimensions of the exemplary cannulas 600 and 600 a will depend onthe intended patient as well as the configuration of the medicamentcartridge. For example, the cylindrical member 604 may have a diameterof 4 mm+/−1 mm and a length of 7 mm+/−1 mm, while the cannula tube 612may have an outer diameter of 0.5 mm, an inner diameter of 0.2 mm and alength of 6-10 mm. With respect to construction and materials, the plug602 and cannula tube 612 may be formed as two separate pieces (asshown), and from two different materials, or integrally formed. Suitablematerials for an integrally formed single cannula include, but are notlimited to, FEP, PTFE, COP, medical grade plastics, and polypropylene.In a two piece arrangement, suitable materials for the cylindricalmember 604 and integral resilient latch 614 include, but are not limitedto PTFE, COP, medical grade plastics, and polypropylene, while thecannula tube 612 may be formed from materials such as PTFE, FEP andother fluoropolymers, and metals such as stainless steel.

Other exemplary instrumentalities for securing a cannula to a baseplateinclude, but are not limited to, other types of latches, includinglatches where a deflectable structure is included on the baseplate orboth the baseplate and the cannula, as well as devices such as frictiondevices, adhesive, pivoting structures and sliding structures. Alatching arrangement may also be associated with the cannula tubeinstead or, or in addition to, the cannula plug. The cannula latch mayalso be omitted and the cartridge through-bore and cannula plugrespectively configured such that friction will maintain the relativepositioning. One example of such a latch-less arrangement is discussedbelow with reference to FIG. 85.

The present baseplates and pump assemblies are not limited to anyparticular connector arrangement. One alternative is the interlockinglatch arrangement illustrated in FIGS. 60 and 61, which may be employedin any of the pump assemblies and baseplates described herein. Theinterlocking arrangement is somewhat similar to the friction arrangementillustrated in FIGS. 53-55 and similar elements are represented bysimilar reference numbers. Here, however, the connection involves amechanical interlock instead of mere friction. More specifically, thebody adherable baseplate 500″′ includes a pair of opposing connectors512 a (one shown) and a hook 514 (not shown). The exemplary connectors512 a have the aforementioned protrusions 520 as well as apertures 530.The side walls (one shown) of the associated pump assembly housing 202′have corresponding mating structures 532, each having a protrusion 534that is sized and shaped to fit into an aperture 530. In the illustratedimplementation, the mating structures 532 are carried within recesses536 and have cam surfaces 538 and flat surfaces 540. As the baseplate500″′ is connected to the pump assembly 200′, which is otherwiseidentical to pump assembly 200, the protrusions 520 will engage the camsurfaces 538, thereby pivoting the connectors 512 a, until the apertures530 are aligned with the mating structures 532. The resilience of theopposing connectors 512 a will then cause them to move into the recess536 and produce the mechanical interlock (or latched state) withprotrusions 534. It should also be noted that the arrangementsillustrated in FIGS. 53-55, 60 and 61 can be reversed, i.e., theconnector structures on the housing moved to the baseplate and connectorstructures on the baseplate moved to the housing, and/or the connectorstructures can be associated with different housing walls. The number ofconnectors may also be increased and decreased, and other latchingarrangements may be employed.

The present baseplates and pump assemblies are not limited to theexemplary structures for securing the baseplate to the associated pumpassembly described above. Other suitable structures for securing abaseplate to a pump assembly include, but are not limited to, guidedslide attachments, mechanical fasteners, magnet arrangements,hook-and-loop attachments, screw-on configurations, and low tackpressure sensitive adhesives. Also, the pump assembly or the baseplatemay be provided with a pocket into which the other may be inserted.

The body adherable baseplate 500 will be, before, during and/or afterthe cartridge 100 and pump assembly 200 are combined therewith, adheredto the patient's skin. To that end, the bottom surface of the platemember 506 carries an adhesive layer 542 (FIG. 55) that releasablyattaches the baseplate 500 to the patient's skin. The adhesive layer 542may cover all, or less than all, of the bottom surface. A removableliner 544 (FIG. 54) may be used to cover the adhesive layer 542 untilthe time of use.

The present inventors have determined that it can be difficult to keepthe cannula fixed and erect in the wound, given that the skin may berough and non-planar and the wound area may be soft, wet and flexible,and that the failure to keep the cannula fixed and erect in the woundmay cause the cannula to bend and occlude. Strong adhesive close to thecannula keeps the cannula fixed and tight. However, strong adhesive ismore likely to irritate and even damage the skin. Thus, although theadhesive layer 542 may consist of a single type of adhesive, theexemplary baseplate 500 may include more than one type of adhesive inthe adhesive layer 542, each serving a different purpose. In theillustrated embodiment, the adhesive layer has a first adhesive 546 anda second adhesive 548 that is stronger (or “more aggressive”) than thefirst adhesive. The first adhesive 546 occupies the majority of theadhesive layer 542 and holds the majority of the baseplate to the skinwith enough strength to prevent separation during normal usage. Thesecond, more aggressive adhesive 548 surrounds the cannula opening 510and keeps the cannula fixed and tight.

In the illustrated example, the second adhesive 546 may cover 0.75-1.25mm around the cannula opening 510, bulging out and intersecting theadjacent corner of the plate member 506. The second adhesive may alsocover 10% of the bottom surface. With respect to the relative strengths,in one example, the peel strength of the first adhesive 544 may be 60oz/inch width+/−20 oz/inch width, and the peel strength of the secondadhesive may be 50-100% more than that of the first. In another example,the first adhesive can have 80% of the strength of the stronger secondadhesive.

The dimensions of the baseplate 500 may correspond to those of theassociated pump assembly. In the context of the exemplary pump assembly200 described above, the plate member may be 1 mm thick, withlength/width relationships such as 42 mm×34 mm, 40 mm×32 mm, and/or39.0-43.0 mm×31.0-35.0 mm.

The exemplary infusion set baseplate 501 illustrated in FIGS. 62 and 63is substantially similar to the body adherable baseplate 500 and similarelements are represented by similar reference numerals. For example, thebaseplate 501 may include a plate member 506′, a cartridge aperture 508(or recess), and connectors 512 (or any of the other connectorstructures described above). Here, however, the baseplate 501 mayinclude an infusion set such as infusion set 503 (as shown) or maysimply be configured to be connected to an infusion set. The baseplate501 may also lack the adhesive layer.

The baseplate 501 in the illustrated example includes structures thatestablish a fluidic connection which extends from the medicamentcartridge, such as cartridge 100, to the infusion set 503. To that end,and referring to FIGS. 62 and 63 the baseplate 501 may have a connectorplug 550 that is configured to be inserted into the cartridgethrough-bore 116. The exemplary connector plug 550 includes acylindrical member 552 with an internal lumen 554, a plurality of inletports 556 located around the perimeter of the cylindrical member andconnected to the internal lumen, and o-ring or other seals 558 onopposite sides of the inlet ports 556. The exemplary connector plug 550may be integral with the plate member 506′ or may be a separatestructure that is secured thereto. The exemplary seals 558 may beintegral with the cylindrical member 552 or may be separate structures,formed from rubber or other appropriate seal materials, that are carriedthereon. A lumen 560 within the plate member 506′ extends to an outletport 562.

The baseplate 501, pump assembly (e.g., pump assembly 200) and cartridge(e.g., cartridge 100) may be respectively configured such that, when thesystem 11 is assembled, the connector plug 550 will be located withinthe cartridge through-bore 116 with the connector plug seals 558 onopposite sides of the reservoir outlet port 118. Fluid flowing into thethrough-bore 116 from the outlet port 118 will enter the inlet ports556, flow through the internal lumen 554, the baseplate lumen 560, andthe outlet port 562 to the infusion set 503.

The exemplary infusion set 503 (FIG. 62), which may be any conventionalinfusion set, may have a hub 564, a cannula 566 extending from the hub,a flexible adhesive-backed wing-type base 568, and a fluid tube 570.Infusion sets with disk-type bases may also be employed. The adhesivemay be a single type of adhesive, or may be two or more differentadhesives as described above. The tube 570 may be removably orpermanently connected to the outlet port 562. The tube 570 may also beany suitable length (e.g., 42 inches). Connectors 572 and 574 may beprovided on the hub 564 and fluid tube 570 in those instances where thehub and fluid tube are separable.

Turning to the exemplary medicament non-delivery baseplate 502illustrated in FIGS. 64 and 65, there may be instances where the userchooses not to use the pump assembly to deliver medicament and desiresto re-plug the medicament cartridge to prevent leakage. Such periods ofnon-delivery may be associated with, for example, the use of analternate pump or syringes to deliver medicament, or the shipment of thepump assembly to a service center.

The medicament non-delivery baseplate 502 illustrated in FIGS. 64 and 65is substantially similar to the body adherable baseplate 500 and similarelements are represented by similar reference numerals. Given the smallsizes of the cartridge 100 and pump assembly 200, users may find iteasier to reseal the cartridge with the medicament non-deliverybaseplate 502 than with the plug 110.

The exemplary baseplate 502 may include a plate member 506, a cartridgeaperture 508 (or recess), and connectors 512 (or any of the otherconnector structures described above). Here, however, the baseplate 502may also include a plug 504 that is configured to prevent flow from amedicament cartridge (e.g., cartridge 100) carried in a pump assembly(e.g., assembly 100). The baseplate 502 may also lack the adhesivelayer.

The exemplary plug 504 includes a cylindrical member 578 and two or moreo-ring or other seals 580. The exemplary plug 504 may be integral withthe plate member 506 or may be a separate structure that is securedthereto. The exemplary seals 580 may be integral with the cylindricalmember 578 or may be separate structures, formed from rubber or otherappropriate seal materials, that are carried thereon. The baseplate 502,a pump assembly (e.g., pump assembly 200) and a cartridge (e.g.,cartridge 100) may be respectively configured such that, when the system12 is assembled, the plug 504 will be located within the cartridgethrough-bore 116 with the seals 580 on opposite sides of the reservoiroutlet port 118, thereby preventing flow.

It should also be noted that the present inventions include kits whichcontain various combinations of baseplates, at least two of thebaseplates being different. Kits may also include such combinations and,in addition, a pump assembly, and/or a medicament cartridge and/or acannula. For example, a kit may include one or more of each ofbaseplates 500 and 502, a kit may include one or more of each ofbaseplates 501 and 502, a kit may include one or more of each ofbaseplates 500, 501 and 502. Kits may also include any of thecombinations recited in the preceding sentence and, in addition, a pumpassembly, and/or one or more medicament cartridges and/or one or morecannulas. The baseplates in such kits may also include the detectioninstrumentalities discussed in Section VI below. The components thepresent kits (e.g., combination of various baseplates) may be stored ina common package, with individual packages for each component ifnecessary, and provided to the user in the common package. Otherinstrumentalities that may be provided in such kits includes, but is notlimited to, inserters that are preloaded with a cannula and cleaningswabs. A recharger may also be provided in a kit that includes a pumpassembly.

VI. Exemplary Baseplate Identification

It should be noted here that, but for the issue of priming, thedispensing procedures associated with an infusion system “patch pump”configuration, which may include a pump assembly 200 and a baseplate 500(FIG. 53), are substantially the same as the dispensing proceduresassociated with a “pocket pump” configuration, which may include a pumpassembly 200 and a baseplate 501 (FIGS. 62-63). With a “patch pump”configuration, priming is not necessary because the volume of theassociated cannula will be very small and there is a direct connectionbetween the cannula and the medicament cartridge (FIG. 50). Priming is,however, required to fill the infusion set tube (e.g., tube 570 in FIGS.62-63) in a “pocket pump” configuration prior to the onset of medicamentdelivery. 20-30 μl may be required to fill the entire infusion set tubeand, accordingly, the priming procedure may involve the rapid deliveryof 10-15 IUs of U-500 insulin to the tube. The present inventors havedetermined that it would be advantageous to prevent users frominitiating a priming procedure when the system is in the “patch pump”configuration, with a cannula positioned to deliver medicamentessentially directly from the medicament cartridge to the patient,because rapidly delivering 10-15 IUs of insulin to the patient couldadversely effect patient health.

To prevent such undesirable outcomes, at least some of the presentbaseplates may be provided with a baseplate identification device and atleast some of the present pump assemblies may be provided with structurethat cooperate with a baseplate identification device in such a mannerthat the pump assembly controller can make a “baseplate type”determination. For example, the baseplate identification devices may becarried by the baseplates and may be detectable by the pump assembly aswell as distinguishable from one another. Once the “baseplate type”determination is made (e.g., baseplate 500 or baseplate 501), the pumpassembly will proceed in a manner, or mode of operation, that isappropriate for the attached baseplate. For example, if the baseplate500 is detected, the controller will not including priming as part ofthe delivery process and, in some implementations, will prevent the userfrom manually implementing a priming procedure. If, on the other hand,baseplate 501 is detected, then the delivery process may includeappropriate priming of the infusion set tube.

A wide variety of baseplate identification instrumentalities andidentification methodologies may be employed, and the present inventionsare not limited to any particular instrumentalities and methodologies.Various illustrative examples of such instrumentalities andidentification methodologies are presented below.

In the exemplary implementation illustrated in FIGS. 1 and 66-68, thebaseplates 500, 501 and 502 respectively have identification devices582-0, 582-1 and 582-2, each of which includes a pair of electricalcontacts. The electrical contacts are located such that each pair willbe aligned with (as well as contact or be otherwise electrically coupledto) a respective two of the three electrical contacts 228, 230 and 232associated with the pump assembly (FIG. 16) when a baseplate is securedto the pump assembly. The electrical contacts 228 and 230 may also beused to recharge the pump assembly battery 238, as is noted above. Forexample, baseplate identification device 582-0 may include electricalcontact pair 228BP/230BP (FIG. 66) that will align with pump assemblyelectrical contact pair 228/230, baseplate identification device 582-1may include electrical contact pair 230BP/232BP (FIG. 67) that willalign with pump assembly electrical contact pair 230/232, and baseplateidentification device 582-2 may include electrical contact pair228BP/232BP (FIG. 68) that will align with pump assembly electricalcontact pair 228/232. The electrical contacts in each pair, which may belocated in recesses 584, are electrically coupled to one another byconductors 586. The conductors 586 may be formed from a low resistancematerial and may be covered with an appropriate electrical insulator.

During use, and after a baseplate has been secured to the pump assembly(e.g., pump assembly 200), the pump assembly controller (e.g.,controller 240) will cause voltage to be applied across the pumpassembly electrical contacts 228, 230 and 232 and may measure resistance(or another suitable variable) between contact pairs 228/230, 230/232and 228/232. The pair that is in contact with two of the baseplateelectrical contacts will have low resistance therebetween, while theother two pairs will have extremely high (e.g., infinite) resistancetherebetween. The pump assembly controller may store information whichindicates that low resistance at contact pair 228/230 is indicative ofbaseplate 500, low resistance at contact pair 230/232 is indicative ofbaseplate 501, and low resistance at contact pair 228/232 is indicativeof baseplate 502. The “baseplate type” determination may, therefore, bemade by simply determining which two of the three pump assemblyelectrical contacts have a low resistance path therebetween.

Turning to FIGS. 69-72, the exemplary pump assembly 200 d is essentiallyidentical to pump assembly 200 and the baseplates 500 d, 501 d and 502 dare essentially identical to baseplates 500, 501 and 502, respectively.Similar elements are represented by similar reference numerals. Here,however, the pump assembly 200 d only includes the tworecharging-related electrical contacts 228 and 230, and the baseplates500 d, 501 d and 502 d respectively include baseplate identificationdevices 588-0, 588-1 and 588-2 that each have two electrical contacts,i.e., electrical contacts 228BP and 230BP. The electrical contacts 228BPand 230BP, which will contact or otherwise electrically couple with thecontacts 228 and 230 when a baseplate is attached to pump assembly, maybe connected by resistors R1, R2 and R3 with different resistor values.The resistor values may be significantly different to reduce thelikelihood of error. For example R1 may be 10 kΩ, R2 may be 22 kΩ, andR3 may be 68 kΩ. Also, in the illustrated implementation, the electricalcontacts 228BP and 230BP are carried in recesses 590. Resistor value tobaseplate type correspondence information may be stored by the pumpassembly controller. During use, and after a baseplate has been securedto the pump assembly (e.g., pump assembly 200 d), the pump assemblycontroller will cause voltage to be applied across the electricalcontacts 228 and 230 and the resistance between the electrical contacts228BP and 230BP will be measured. The “baseplate type” determination maybe made based on this resistance measurement and a comparison of themeasured value to the stored information.

The exemplary electrical contacts described above may be formed frommaterials such as copper or nickel. Also, although the surfaces of theelectrical contacts are generally planar in the illustrated embodiments,the electrical contacts are not limited to any particular configuration.For example, opposing metallic half balls may be employed with properaccommodation on the pump assembly and baseplate.

Other exemplary baseplate identification instrumentalities areillustrated in FIGS. 73-75. Here, the baseplates 500 e, 501 e and 502 e,which are otherwise identical to baseplates 500, 501 and 502,respectively, carry baseplate identification devices 591-0, 591-1 and591-2 with different patterns of optically identifiable targets. Forexample, the optically identifiable targets may be reflective targets592 a and occluded targets 592 b. The associated pump assembly (e.g.,pump assembly 200 d) may be provided with an emitter/detector 593 that“reads” the patterns of optically identifiable targets and transmits apattern signal to the pump assembly controller (e.g., controller 240)indicative of the pattern that has been read (e.g., 0, 1, 1 for thepattern illustrated in FIG. 74). Pattern to “baseplate type”correspondence information may be stored by the pump assemblycontroller, and the controller may identify the baseplate based on thepattern signal. Additionally, the baseplate identification devices591-0, 591-1 and 591-2 may be carried or formed directly on thebaseplate, or may be carried on structures (e.g. decals) that aresecured to the baseplate.

Other exemplary baseplate identification instrumentalities areillustrated in FIG. 76. Here, the baseplates 500 f, 501 f and 502 f,which are otherwise identical to baseplates 500, 501 and 502,respectively, carry baseplate identification devices 594-0, 594-1 and594-2 in the form of resonant circuits with different resonantfrequencies. The associated pump assembly (e.g., pump assembly 200 d)may be provided with an RF transmitter 595, including an RF transmitterantenna, a detector-demodulator, and RF electronics. The RF transmitter595 may be used to detect the frequency of a resonant circuit inproximity thereto and to provide such frequency information to thecontroller. Exemplary resonant frequencies for the baseplateidentification devices 594-0, 594-1 and 594-2 include, but are notlimited to, 10 kHz, 20 kHz and 30 kHz, and frequency to “baseplate type”correspondence information may be stored by the controller.

Still other exemplary baseplate identification instrumentalities areillustrated in FIG. 77. Here, the baseplates 500 g, 501 g and 502 g,which are otherwise identical to baseplates 500, 501 and 502,respectively, carry baseplate identification devices 596-0, 596-1 and596-2 in the form of magnets that create different magnetic fields. Theassociated pump assembly (e.g., pump assembly 200 d) may be providedwith a sensor 597, such as a Hall-effect sensor or a magnetoresistivesensor, that reads the magnetic field of the associated baseplateidentification device, and sends a signal corresponding to the sensedmagnetic field to the controller. Magnetic field to “baseplate type”correspondence information may be stored by the controller.

Turning to FIG. 78, the exemplary baseplate identificationinstrumentalities illustrated therein include baseplate identificationdevices 598-0, 598-1 and 598-2 in the form of RFID tags, each of whichemits different identification data in response to being interrogated.The baseplate identification devices 598-0, 598-1 and 598-2 arerespectively carried by baseplates 500 h, 501 h and 502 h, which areotherwise identical to baseplates 500, 501 and 502. The associated pumpassembly (e.g., pump assembly 200 d) may be provided with an RFID reader599 that interrogates the associated identification device, and sends asignal corresponding to the identification data to the controller.

The present baseplates and pump assemblies are not limited to theexemplary identification instrumentalities described above. By way ofexample, but not limitation, other identification instrumentalitiesinclude protrusions on the plate that depress buttons, or combinationsof buttons, on the bottom surface of the pump assembly housing. Anotherexample includes depressible pins that extend from the bottom surface ofthe pump assembly housing, such that they will be pressed by an attachedbaseplate. Here, different baseplates may be provided with differentcombinations of indentations that will be aligned with the pins, toprevent depression thereof, when the baseplate is attached. It shouldalso be noted that the present baseplates and pump assemblies are notlimited to identification instrumentalities that require the baseplateto be completely or partially attached to the pump assembly prior to theidentification procedure. Instrumentalities that merely require suitableproximity (including those that involve RFID technology) may beemployed.

VII. Exemplary Basic Operation and Use

At the most basic level, use of the exemplary infusion pump system 10(or 11) illustrated in FIG. 1 involves inserting a new medicamentcartridge 100 into the pump assembly, connecting the baseplate 500 (or501) to the pump assembly, gaining subcutaneous access, and initiating amedicament delivery operation. In some instances, use may involveadditional steps such as removal of a previously inserted cartridge(whether empty or not) and battery recharging. Various aspects of thebasic operation of the present systems are described below. Operation ofa system does not require all of the steps each time the system isdeployed, and the order of some of the steps may be changed. Operationis also discussed below, in the exemplary context of the above-describedcartridge 100, pump assembly 200′ and patch pump baseplate 500′, throughthe use of a flow chart (FIG. 79) as well as through illustrations ofthe exemplary system itself in various states (FIGS. 80-90). Thediscussion is, however, equally applicable to other patch pumpimplementations, as well as to pocket pump implementations with minorvariations. Also, unless otherwise indicated, the actions anddeterminations performed by the pump assembly 200′ are controlled bycontroller 240 (FIGS. 18 and 84) and references to the controller areomitted in the interest of brevity.

Referring first to FIG. 79, use of the present systems may involveremoval of a cartridge from a pump assembly. This may occur (in someinstances automatically) when the plunger pusher 250′ is at the end ofthe pusher stroke (Step S101) and a “replace cartridge” report ispresented (Step S102), or when the controller receives a user-initiated“replace cartridge” signal from the remote control 1000 (Step S103). Theuser may desire to replace a cartridge before it is empty for a varietyof reasons such as, for example, to accommodate the user's sleep ortravel schedule, when the medicament appears cloudy or otherwiseexhibits a loss of effectiveness, when a dispensing problem arises, ordue to a prescribed change in medicament. Whether automatic oruser-initiated, the plunger will be returned to the fully retracted homeposition (Step S104). The user may then obtain a new cartridge 100, anew baseplate 500′, a new cannula and inserter, the remote control 1000(if not already at hand), and the battery recharger 700 (Step S105). Thecartridge 100, pump assembly 200′, baseplate 500′ and cannula may thenbe removed from the skin, and the baseplate, cartridge and cannuladiscarded (Steps S106 and S107). The battery 238 may be recharged withthe recharger 700 (Step S108) in the manner described in Section IV-Jabove with reference to FIGS. 49-50.

A new cartridge 100 may then be inserted in the pump assembly 200′ (StepS109). In particular, as illustrated in FIG. 80, because the pusher 250′is in a retracted home position, the slidable latch 412 a is unlockedand the latch member 442 can be pushed to the rearward position, therebyfacilitating cartridge insertion, as described in Section IV-F abovewith reference to FIGS. 32-35A. The latch member 442 will return to thelocked position (FIG. 81) when released, thereby pushing the cartridge100 against the chassis 244.

The plug 110 may remain in the cartridge through-bore 116 should theuser desire to perform the pusher zeroing procedure (or “zeroingprocedure”) described in Section VIII-B below with reference to FIG. 91(Step S110). The zeroing procedure may also be an automatic aspect ofpump operation. The user may use, for example, the remote control 1000to initiate the zeroing procedure (FIG. 81) which involves brieflyadvancing the pusher 250′ (FIG. 82), thereby locking the latch 412 a andrigidly fixing the position of the cartridge 100 against the chassis 244in a held position within the cartridge receiving area 220. If theresults of the zeroing procedure are negative, the pusher 250′ iswithdrawn (FIG. 83), thereby unlocking the latch 412 a. The medicamentcartridge 100 is removed and discarded, a new cartridge is inserted, andthe zeroing procedure is repeated (Steps S111, S112, S113 and S114).Alternatively, if the results of the zeroing procedure are positive, thepusher 250′ is withdrawn, the plug 110 is removed and the baseplate 500′may be secured to the pump assembly 200′, as shown in FIG. 84 (StepsS115 and S116). As discussed above in Section IV-F above with referenceto FIG. 35A, the slidable latch member 442 will seat in the baseplatelatch indentation 509 to properly align the pump assembly 200′ andbaseplate 500′.

A cannula inserter (or “inserter”) may then be secured to the pumpassembly 200′ (Step S117). One exemplary inserter, which is generallyrepresented by reference numeral 800 in FIG. 85, may include a movablemember 802 within a housing 804, and a trigger-type actuator 806 thatacts on the movable member. The exemplary actuator 806 may have arotatable trigger 808 and a compressed spring or other biasing device810. A trocar 812 is carried on the movable member 802. A cannula 600′is pre-mounted on the trocar 812 such that the sharp end of the trocarextends beyond the cannula tube 612. The inserter 800 may also beconfigured to withdraw the trocar back into the housing 804 after thecannula is deployed.

It should be noted here that the exemplary cannula 600′ is substantiallysimilar to the cannula 600 described in Section V above with referenceto FIGS. 56-57 and similar elements are represented by similar referencenumerals. Here, however, the cannula 600′ does not include a latch.Instead, the respective configurations (e.g., shape, size and materials)of the cartridge through-bore 116 and the cannula plug 602′ are suchthat friction therebetween will maintain the relative positioning aftercannula deployment. The cannula plug 602′ may also be formed from twodifferent materials, e.g., a more rigid inner material to providestructural support and a softer outer material for sealing. Thediscussion concerning deployment of the cannula 600′ is, of course,equally applicable to cannula 600, cannula 600 a and/or any othercannula that may be used in conjunction with the present pump assembliesand baseplates.

The user may clean the skin surface S onto which the baseplate 500′ willbe adhered, and the liner 544 may be removed to expose the adhesivelayer 542, as illustrated in FIGS. 85 and 86 (Steps S118 and S119).Turning to FIG. 87, the unit consisting of the cartridge 100, pumpassembly 200′, baseplate 500′, cannula 600′ and inserter 800 may beadhered to the skin surface S (Step S120). The inserter actuator 806 maythen be actuated (FIG. 88) by rotating the trigger 808, thereby allowingthe spring 810 to drive the movable member 802 towards the patient (StepS121). The cannula plug 602′ will be properly seated in the cartridgethrough-bore 116, and the cannula tube 612 will be subcutaneouslydeployed, at the end of the movable member stroke. The inserter 800 maythen be removed (FIG. 89, Step S122).

In some implementations, the pump assembly may be provided withstructure (not shown) that performs the function of determining whetheror not the cannula is properly inserted (Step S123). If not, an errormessage will be provided to the user (Step S124).

Finally, as shown in FIG. 90, the remote control 1000 may be used toinitiate a particular medicament delivery operation (Step S125). Thedelivery operation may follow a predetermined delivery profile (e.g. aparticular basal rate, a series of time-spaced bolus deliveries, or somecombination thereof) that is equated to motor rotations, at particularrates and times, required to deliver medicament in accordance with theprofile. The profile may be input by the user with the remote control1000 and stored by the controller 240. For example, as described below,the remote control may store a number of different delivery profiles andbolus deliveries from which the patient can choose. Such profiles maycorrespond to, for example and depending on the medicament, days wherevigorous exercise is expected, days where it is not, incidences ofincreased pain, etc. Alternatively, or in addition, the profile storedin the controller may be set by a clinician's programming unit.

The discussion above is also applicable to use of the “pocket pump”system 11. Minor variations in the above-described procedure include,for example, use of the baseplate 501, deploying the infusion set 503instead of a cannula, and priming of the infusion set tube.

VIII. Exemplary Operational Methodologies

Various methodologies are presented here in the context of the exemplarystructures described in the preceding sections, and illustrated in FIGS.1-90, for the purpose of explanation only. Although the presentmethodologies may employ the structures described above, they are notlimited thereto. Additionally, the alarms, reports and othernotifications associated with the methodologies described below may beprovided in audible, visible and/or tactile form. A pump assembly mayprovide audible, visible and/or tactile notifications. A remote controlmay also provide audible, visible and/or tactile notifications as analternative to, or in addition to, any notifications provided by a pumpassembly. Additionally, embodiments of the present inventions mayincorporate any one of the methodologies described below, or all of themethodologies described below, or any and all combinations of less thanall of the methodologies described below.

A. Exemplary Cartridge Position Check

Given the relatively small size of the systems described above, thepresent inventors have determined that it would be desirable todetermine whether or not a cartridge (e.g., cartridge 100) has beenproperly inserted into (or “positioned in” or “seated in”) a pumpassembly (e.g., pump assembly 200) cartridge receiving area. Forexample, it may be desirable to make such a determination when thecartridge is initially inserted into a pump assembly, and prior to thepusher zeroing procedure discussed in Section VIII-B below. Otherprocedures, such as pusher zeroing procedure, may also startautomatically after the position check.

A variety of structures may be employed in such a position check. Forexample, as discussed in Section IV-H above with reference to FIGS. 41and 42, an exemplary cartridge and pump assembly may be provided with apressure sensor 234 that includes a detectable structure on thecartridge portion 120 (e.g., a magnet) and a detector on the pumpassembly portion 236 that responds to the detectable structure (e.g., asensor that responds to changes in magnetic fields). Thepre-pressurization “at rest” position of the cartridge portion 120within the cartridge receiving area 228 (and relative to the chassiswindow 287) is also closely controlled by, for example, the spring biasclips 268, the latches 412 and 412 a and structures 494 described inSection IV-F above with reference to FIGS. 18, 23-26, 32-35A and 38. Asa result, the controller 240 may use the signals from the pump assemblyportion 236 to determine whether or not the cartridge has been properlypositioned. In the exemplary context of magnet-based sensors, thecontroller would compare the measured magnetic field signals to expectedmagnetic field signals to determine whether or not the cartridge isproperly positioned.

Accordingly, and referring to FIG. 91, a method of checking cartridgeposition may include sampling the output of the pump assembly portion236 of a pressure sensor 234 (Step S201) and determining whether or notthe output is above a predetermined threshold and stable (Step S202). Ifnot, then a “cartridge not installed” alert may be provided (Step S203)so that the user can take appropriate action, such as inserting a newcartridge or returning the pump to the manufacturer. If the cartridge isproperly positioned, then the system will proceed with subsequentprocesses such as the pusher zeroing procedure described below.

It should also be noted here that in other implementations, structuresother than the pressure sensor 234 may be used to determine whether ornot the cartridge 100 is properly positioned in the pump assembly 200.For example, the cartridge barrel 102 may be provided with a pressureresponsive structure that will not be isolated from the reservoir, aswill the sensor cartridge portion 120 by the plug 110, during the pusherzeroing procedure described below. Here, a pressure-based cartridgeposition check may be performed at the onset of a pusher zeroingprocedure. Switches, electrical contacts or other devices may also beemployed.

B. Exemplary Pusher “Zeroing” Procedure

As discussed at great length above, precision is very important todispensing procedures that involve highly concentrated medicaments suchas U-500 insulin. The present inventors have determined that one aspectof dispensing precision is associated with the distance that the plungerpusher must travel, from the initial home position, before it willengage the cartridge plunger and begin to drive medicament out of thereservoir. Given that there may be some tolerances associated withcartridge manufacture and initial seating of the cartridge within thepump assembly, this distance may vary. Thus, a dispensing process basedon an estimate/measurement of this distance at the time of manufacturemay result in under delivery or over delivery in some circumstances.

The pusher zeroing procedure described below obviates this issue byprecisely determining and/or setting, prior to actual dosing, exactlyhow far the plunger pusher 250 must travel before it will engage thecartridge plunger 106. This procedure may be performed each time acartridge 100 is inserted into a pump assembly 200 and, in at least someinstances, is performed after the position of the cartridge is checkedin the manner described in the preceding section. Generally speaking,the zeroing procedure is performed when flow from the cartridge 100 isblocked by the plug 110. A test load (e.g., ten pounds) is applied tothe cartridge 100 with the plunger pusher 250 to fully seat thecartridge and to generate a motor stall. Misalignment or misplacement ofthe cartridge 100 within the pump assembly 200, such as from a raisedchip or other debris on mating surfaces, is either removed oraccommodated by local deformation of the cartridge under the test load,thereby precluding subsequent cartridge movement during medicamentdelivery. The motor stall is presumed to be due to hydraulic lock and,therefore, indicative of the plunger pusher 250 engaging the plunger 106of a plugged cartridge 100.

Referring again to FIGS. 81-83 and 91, one exemplary implementation ofthe zeroing procedure may be practiced in conjunction with pump assembly200′. The zeroing procedure, which is equally applicable to pumpassembly 200, commences by advancing a plunger pusher 250′ intoengagement with the cartridge plunger 106 (FIG. 81) to increase thefluid path pressure (Step S204). The encoder 396 or other monitoringdevice is sampled to determine whether a motor stall occurs as thepusher 250′ continues to be advanced (Steps S205 and S206). One exampleof such a stall is illustrated in FIG. 82. The pusher 250′ may beadvanced up to a predetermined allotted distance (e.g., 0.5 mm) from thehome position (FIG. 18), which corresponds to a predetermined number ofencoder signals. The allotted distance is a distance that is sufficientto make contact with cartridge plunger 106 under normal conditions.

The pusher may be initially advanced at a relatively fast speed, andthen advanced at a relatively slow speed (e.g., ½ of the faster speed)until the lack of encoder signals evidences that the motor is notturning. The faster speed can occur over a distance of 0.3 mm and theslower speed can occur over a distance of 0.2 mm. The slower speed is a“searching” speed employed over the portion of the allotted distancewhere it is anticipated that the pusher 250′ will contact the plunger106. The lower speed reduces the force of the impact. The faster speedis used to speed up the process over the portion of the allotteddistance where it is less likely that the pusher 250′ will contact theplunger 106. Also, the pusher 250′ may be advanced at a controlledtorque, or limited force, so that the motor will stall with the leastamount of force possible for reliable results, in order to reduce theload on the system (e.g., the bearings and the battery).

If a motor stall does not occur within the allotted distance, the systemcontroller 240 may determine that the associated cartridge 100 is eithernot new, not full, was improperly made or filled, or is otherwisedefective and may preclude its use (Step S208). In those instances wherethe cartridge is not full, the preclusion is useful because, forexample, the associated dispensing program may be based on a fullcartridge with a known volume of medicament.

If the motor 358 does stall within an acceptable encoder count range,i.e., at or before the allotted distance, then the pusher 250′ isretracted a predetermined distance by running the motor in reverse,which ends the process (Step S209). One example of pusher retraction isillustrated in FIG. 83. The retraction distance may be, for example,0.001 to 0.005 inch (0.025 mm to 0.125 mm). The retraction distance mayalso be equated to dispensed medicament, e.g., 1 to 20 μl worth, or 5.5to 6.5 μl worth. In any event, at the onset of dosing, the distancebetween the plunger pusher and the plunger is precisely set and can betaken into account as movement of the plunger pusher is controlled.

The advancing-retracting process can be repeated a few times to account,for example, for variability of the interface between the lead screw 360and nut 364 (FIG. 23). The advancing-retracting process can be alsorepeated using a light force (e.g., two pounds) followed by a strongerforce (e.g., four to five pounds) to confirm that the first motor stallwas due to torque and not some other cause. Repeating the processincreases the likelihood that the “zero” distance between the plungerpusher 250′ and the dry side of the plunger 106 will be preciselyestablished.

C. Exemplary Occlusion Detection

Various structures in the exemplary cartridges and pump assemblies maybe used to detect occlusions in a cartridge, cannula or infusion settube. Although precise occlusion detection may be desirable in anyinfusion pump, it is especially desirable in those instances where veryhigh concentration medicament is dispensed. For example, someconventional insulin pumps alert the patient after approximately 30 μlof missed delivery without an undue number of false alarms. While thislevel of fidelity may be adequate in the context of U-100 insulin, where30 μl equates to 3 IUs of insulin, it would result in a much moreproblematic 15 IUs of missed delivery in the U-500 context. Occlusionsmay also lead to other undesirable outcomes. For example, continuing todrive the motor in the presence of an occlusion may lead to cartridgeleakage and/or damage to various aspects of the drive mechanism. Thestructures described above and methodologies described below addressthese issues.

One exemplary dispensing method, which includes occlusion detection, isillustrated in FIGS. 92 and 93. The occlusion detection aspect of theexemplary method includes monitoring of the motor encoder 396 as well asmonitoring of the pressure sensor 234. It should be noted, however, thatonly one of the two may be monitored in the occlusion detection contextin other implementations.

Referring first to FIG. 92, at the initiation of a dosing operation, thefirmware counter of the controller 240 is loaded with the number ofencoder counts required to advance the pusher 250 a distancecorresponding to the desired drug dose (Step S301). For example, in someimplementations, a single dose of 1 μl (or 0.50 IU) of U-500 insulinwould equate to 14.4 motor revolutions. In other words, in the contextof the exemplary embodiment illustrated in FIG. 23, 14.4 motorrevolutions will cause the drive screw 360 to drive the plunger pusher250 (and cartridge plunger 106) a distance sufficient to force 1 μl fromthe reservoir 104.

Motor rotation begins, which causes the pusher 250 to advance, and thecounter is decremented in response to signals from the encoder 396 (StepS302). Detected increases in pressure from the pressure sensor 234and/or signals from the encoder 396 indicative of a stalled motor 358result in the generation of an “occlusion” report (Steps S303, S304 andS305). In at least some implementations, the motor 358 will also bedisabled (i.e., motor excitation ceases). Various exemplary occlusiondetectors are discussed in greater detail in Section IV-H above withreference to FIGS. 41 and 42. In response to the detection of anocclusion, the user may be instructed to remove and replace thecartridge 100 as well as the baseplate 500 (and associated cannula) orbaseplate 501. Also, in at least some implementations, the plungerpusher 250 will be automatically withdrawn from the cartridge andreturned to the home position, as described in Section VIII-F below, inresponse to a detected occlusion. This readies the system for cartridgeremoval and replacement.

Absent an occlusion, the dispense operation will continue until thecounter reaches zero (Step S306), which indicates that the desired dosehas been delivered. At that point, the controller 240 will control themotor 358 to rotate until the next step count from the encoder 396, andwill thereafter disable the motor (Steps S307 and S308). The controller240 may, however, continue to monitor the encoder 396 (Step S309) todetermine whether or not there is encoder (and motor 358) rotation inthe absence of motor excitation (Step S310). If forward rotation of themotor 358 is detected in the absence of motor excitation (Step S311),which indicates that the motor 358 is at least attempting to drive theplunger pusher 250 in the dispensing direction, an error is reported(Step S312). If reverse rotation is detected in the absence of motorexcitation, which is indicative of the plunger pusher moving away fromthe cartridge plunger due to, for example, system load or compliance,the appropriate number of encoder counts will be added to the nextdispense dose (Step S313).

As alluded to above, occlusions may be detected by monitoring rotationof the motor 358 (e.g., by way of the encoder 396) and/or by monitoringpressure (e.g., with the sensor 234). With respect to pressure, apredetermined rate of pressure change (or ΔP/ΔT) or pressure above apredetermined threshold may be indicative of an occlusion. The presentmethods may employ one of, any two of, or all three of rotation, ΔP/ΔTand threshold, as shown in FIG. 93. Motor rotation may be monitoredduring a dispense operation by continuously sampling the encoder 396with the controller 240 (Step S401). If the encoder 396 does not senserotation of the motor 358 during a dispense operation, the controller240 will consider the motor 358 to be stalled due to, among otherthings, an occlusion (Step S402) and report accordingly (Step S403).Alternatively, or in addition, the controller 240 may repeatedly samplethe output of the pressure sensor 234 (Step S404) and use a most recentvalue, the immediately preceding value, and the time period therebetweento create ΔP/ΔT values (Step S405). If the ΔP/ΔT values remain over apredetermined magnitude (e.g., 2 psi/sec.) for a predetermined period oftime (e.g., 2 sec.), the controller 240 will consider the pressureincrease to be due to an occlusion (Step S406) and report accordingly(Step S403). Alternatively, or in addition, the controller 240 mayrepeatedly sample the output of the pressure sensor 234 (Step S407) andcompare the output to a predetermined threshold value (Step S408). Insome instances, the controller 240 will provide a “possible occlusion”alert in response to any sample that is over the threshold value (e.g.,the expected “occluded” value) and, regardless of whether the “possibleocclusion” alert is provided, subsequent samples will be used todetermine whether or not the condition persists (Step S409). If the“over the threshold” condition persists for a predetermined period(e.g., 1 sec.), and if a comparison of subsequent samples to the priorsample is not indicative of a future reduction below the thresholdvalue, then the controller 240 will consider the pressure increase to bedue to an occlusion (Step S410) and report accordingly (Step S403).

D. Exemplary Accounting for Unpowered Motor Reverse

The present inventors have determined that there may be some instanceswhere an unpowered motor unintentionally rotates in reverse due to, forexample, system load or compliance. Such load and compliance may beassociated with a build-up in force in the gears which releases itselfby the gears turning in the reverse direction when the motor is notenergized. When this occurs, the motor is rotated in reverse. At theother end of the gear assembly, the plunger pusher, which has previouslybeen brought into engagement with the cartridge plunger, may (or maynot) pull away from the plunger. The initial motor turns in the nextdelivery procedure (or “dose” or “delivery cycle”) will, in essence,simply rebuild the force in the gears and, if not already the case,bring the pusher back into contact with the plunger. As a result, thevolume of medicament actually delivered to the patient in that dose willbe less than expected.

In order to account for, or correct for, the delivery error that wouldotherwise be associated with this condition, the pump assembly mayinclude an encoder 396 which senses rotations of the motor in both theforward and reverse directions. The controller 240 may be configured todetermine from the encoder signals the amount of reverse rotation and toadjust the dispensing program accordingly so that the net result is theoverall intended result.

One example of such a correction process is illustrated in FIG. 94. Atthe onset of a dispensing procedure (Step S501), the number of motorrevolutions corresponding to the intended delivery is calculated and set(Step S502). Using the example above, a single dose of 1 μl (or 0.50 IU)of U-500 insulin may equate to 14.4 motor revolutions. The controller240 will control the motor 358 to operate for the set number ofrevolutions (Step S503), unless one of the other alarm conditionsdescribed below with reference to FIG. 100 occurs. The controller 240will then unpower the motor 358, and the motor will remain unpowered,until the next dosing (Step S504). Should the motor 358 rotate inreverse, as evidenced by signals from the associated encoder 396, thenumber of reverse rotations (or “reverse count”) will be counted andstored until the next dosing (Steps S505 and S506). When the next dosingcommences, the reverse count will be added to calculated and set numberof rotations for that next dosing (Step S503). For example, if therewere 2 reverse rotations prior to a dosing that equates to 14.4 motorrevolutions, the controller would control the motor to perform 16.4revolutions for that dosing.

E. Exemplary Motor Stopping

The present inventors have determined that another aspect of motorcontrol which can effect the precision of medicament delivery is motorstopping. Briefly, when a controller cuts off power to a motor, themotor will continue to rotate, in a now uncontrolled state, due to itsown momentum and the momentum of other rotating aspects of the drivemechanism. The plunger pusher will continue to travel in the forwarddispensing direction, thereby driving the cartridge plunger, as themotor continues to rotate. Although one could simply cut off power a fewrevolutions prior to the end of a delivery cycle, the precise number of“extra,” post cut-off revolutions is difficult to accurately andconsistently estimate. As such, the simple act of turning the motor onand off, from dose to dose, can lead to under delivery and/or overdelivery error due to the uncontrolled movement of the plunger pusher.

One exemplary method of controlling a motor such as a stepper motor 358with a controller such as controller 240 is graphically illustrated inFIG. 95. In particular, the speed of motor is increased from zero at thebeginning of the dispensing procedure (e.g., a single dose) and is thenmaintained at a constant rate. At a predetermined point prior to the endof the dispensing procedure (e.g., three revolutions prior), which islabeled “begin motor stop process” in FIG. 95, the frequency of thepower waveform delivered to the motor 358 will be slowly decreased.Positive control over the motor 358 is maintained as the velocity of theplunger pusher 250 decreases from its propelling velocity to a completestop, where the speed equals zero and the dosing ends. Maintainingpositive control of the motor 358 in this manner allows the number ofturns associated with a motor stoppage to be precisely controlled as isshown with a solid downwardly sloping line in FIG. 95. As a result, theintended number of rotations associated with stoppage will be the actualnumber of rotations, the distance of pusher travel will be the intendeddistance, and dispensing precision will be maintained. For purposes ofcomparison, stopping the motor by simply cutting off power at the samepredetermined point may result in too much or too little rotation, as isshown with dashed lines. As a result, the distance of plunger travel(and dispensed volume) may be more or less than intended.

Accordingly, by employing the above-described stopping method, thecontroller can cause the motor 358 to propel the pusher 250 against themedicament reservoir plunger 106 according to a medicament dispensingprogram, having a plurality of individual dispensing operations, withoutstoppage related losses in precision. Also, the predetermined pointprior to the end of the dispensing procedure at which frequency of thepower waveform begins to decrease may vary from system to system.Although a three revolution slow down period is employed in theillustrated example, that number may be increased or decreased, and neednot be a whole number.

F. Exemplary Automatic Plunger Pusher Retraction Procedures

For purposes of convenience and safety, the present pump assembly may beconfigured such that the plunger pusher is automatically retracted outof the associated medicament cartridge to the home position when thecartridge reaches the empty state, as evidenced by an encoder count or amotor stall, and/or when there is a motor stall due to an occlusion orother mechanical issue.

Referring to FIG. 96, the controller 240 will monitor the encoder 396 todetermine whether the motor 358 has stalled or the encoder count hasreached the number that is indicative of an empty cartridge (Step S601).Such a stall would be evidenced by the cessation of encoder counts andcould, for example, be the result of the plunger pusher 250 driving thecartridge plunger 106 into the cartridge end wall 119 (FIG. 25), or anocclusion, or a mechanical issue. The “empty” number could reflect theexact number of motor rotations that would result in, for example, thecartridge plunger 106 reaching the end wall 119 (FIG. 3A). However, inorder to prevent damage to the drive mechanism that could result fromthe plunger pusher 250 repeatedly driving cartridge plungers into afixed wall, the “empty” number could instead reflect slightly less thanthe exact number of motor rotations. It should also be noted that theencoder count may be adjusted to account for unpowered reverse motorrotations, during the life of the associated cartridge, in the mannerdescribed above with reference to FIG. 94.

Other issues notwithstanding, so long as the motor 358 has not stalledand the encoder count is not indicative of an empty cartridge,dispensing will be allowed to continue (Step S602). If, on the otherhand, the motor 358 has stalled or the encoder count is indicative of anempty cartridge, then the controller 240 will control the motor to runin the reverse, pusher retraction direction (Steps S603 and S604). Theretraction speed may be relatively slow, as compared to a user-initiatedretraction, so as to conserve battery power. For example, a relativelyslow retraction may take 1 minute, or between 1.5 and 2.5 minutes, whilea faster user-initiated retraction may take 30 seconds, or between 20and 40 seconds. The user is not inconvenienced by the slower automaticretraction because it is occurring automatically at a time when the useris most likely not waiting for it to end, as would be the case in auser-initiated retraction.

At least initially, the retraction will take place at the fullretraction speed (Step S605). The speed may be reduced to a slower speedwhen the pusher 250 approaches the fully retracted home position (StepS606). For example, the speed may be reduced at a distance from thefully retracted position that corresponds to 10% of the total pushertravel distance (i.e., the distance between fully retracted and fullyextended). Withdrawal will continue until the controller 240 determinesthat the pusher has reached the fully retracted position (e.g., by wayof position detector 398 in FIG. 29), at which time the motor 358 willbe stopped (Steps S607 and S608). To that end, it should be noted thatthe lower speed over the last 10% of pusher travel reduces thelikelihood that the pusher 250 will damage the switch 398 or otherposition detector during impact therewith.

G. Exemplary Gear Assembly Verification Procedure

One aspect of the present pump assembly 200 that may require periodicoperational verification is the gear assembly (e.g., gear assembly 362in FIG. 19) and, for example, the interfaces thereof. One exemplary gearassembly verification procedure (“GAV procedure”) is illustrated in FIG.97. The exemplary GAV procedure will typically be performed by acontroller when there is no medicament cartridge in a pump assembly inorder to avoid the possibility of medicament being unintentionallydispensed. For example, controller may be configured to perform the GAVprocedure each time the plunger pusher is returned to the fully retracedhome position (e.g., against a hard stop), which is commonly associatedwith cartridge removal, or during a pusher zeroing procedure.Alternatively, or in addition, the GAV procedure may be a userimplementable procedure initiated through operation of the remotecontrol 1000.

Upon initiation of the GAV procedure (Step S701), the controller 240 maydetermine whether or not a cartridge 100 is within the pump assembly 200by, for example, a method similar to those described in Section VIII-Aabove. Here, however, the controller need only determine whether acartridge is in the pump assembly at all, as opposed to determiningwhether a cartridge is precisely located within the cartridge receivingarea. If a cartridge is present, then the procedure is discontinued andan error message is provided to the user (Steps S702 and S703). If nocartridge is present, then the controller 240 determines whether or notthe plunger pusher 250 is in the fully retracted home position and, iffor some reason it is not, the controller automatically retracts theplunger pusher (Steps S704 and S705). Alternatively, the user could beinstructed to retract the pusher 250 through operation of the remotecontrol 1000.

Relatively low torque is then applied to the gear assembly 362 by themotor 358 in the reverse direction (Step S706). For example,approximately 20-70% (or 50%), or less than 20%, of the torque (e.g.,5-10 mNm) that is applied in the forward dispensing direction duringnormal delivery may be applied in the reverse direction. This may beaccomplished by controlling power in the manner described in SectionIV-M above. It should be noted here that there may be some built-up gearcompression that will allow reverse motor rotation despite the fact thatthe plunger pusher has been fully retracted. Other situations aredescribed below.

The power pulses will be sustained for a period corresponding to apredetermined number of motor revolutions (e.g., 50 revolutions).Signals from the encoder 396 and, therefore, motor rotation may bemonitored. If the encoder signals indicate that the motor 358 hasrotated at least a predetermined number of revolutions (e.g., 20revolutions), precisely synchronized to motor driving sequence ofpulses, the controller 240 determines that the motor is disconnectedfrom the gear assembly 362 and creates a “drive error” signal (StepsS707 and S708). If, on the other had, the encoder signals indicate thatless than the predetermined number of revolutions have occurred and thatthere is not a 1:1 correlation between the driving pulses and theencoder signals, then the controller determines that gear assembly 362is intact and creates a “drive OK” signal (Step S709). In other words,and somewhat counter intuitively, the controller 240 determines that thegear assembly 362 is not operating properly if signals from the encoder396 indicate that the motor 358 is synchronized with the motor drivingpulse sequence, and determines that the gear assembly is operatingproperly if signals from the encoder indicate that the motor is notsynchronized with the motor driving pulse sequence.

In those instances where the plunger pusher 250 has been fully retractedand there is no built-up gear compression that would allow reverserotation of the motor 358 under normal circumstances, the process may beadjusted slightly. Here, the motor 358 may be driven first in theforward direction and then in the rearward direction several times toverify whether or not the motor stalls after the same number of pulses(as determined by, for example, the switch 398 in FIG. 29).

As alluded to above, a GAV procedure may be performed each time themotor 358 stalls. During zeroing and, in some embodiments, duringhoming, the motor 358 is stalled at controlled torque either against theplunger (zeroing) or against a hard stop (homing). During thisprocedure, the motor 358 is controlled to advance the mechanism at aknown controlled torque while the motor encoder 396 is monitored forrotation. Correct operation requires the system to stall (encoder 396ceases to turn while driving the motor 358) at a predetermined position.If the encoder 396 continues to indicate motor rotation while drivesignals are being sent to the motor 358, past the region of expectedmotor stall, it indicates the possibility of gear assembly failure.

IX. Exemplary Remote Controls and Associated Methodologies

The present infusion pumps may be used in conjunction with a widevariety of remote controls. Such remote controls may be used to, forexample, allow the user to transmit instructions to the pump assembly orfacilitate communication between the pump assembly and the user (e.g.,an alarm condition message or other message concerning the conditions ofthe pump assembly).

The particular type of remote control may depend on the desired level offunctionality for a particular user. A key fob type remote control whichhas one to four buttons may be provided in those instances where theuser's control options are to be limited to, for example, starting andstopping medicament delivery procedures and withdrawing the plungerpusher from the cartridge. On the other end of the spectrum,commercially available devices with full-function user interfaces (e.g.,a keyboard and a display, or a touch screen display), such as mobiletelephones and personal digital assistants, may be programmed to providethe desired level of remote control functionality.

One exemplary remote control, which is generally represented byreference numeral 1000 in FIGS. 98 and 99, is configured and dimensionedto be easily grasped and manipulated in the user's hand. The exemplaryremote control 1000 may include a power supply 1006 (e.g., one or morereplaceable or rechargeable batteries), a sending and receiving antenna1008 that is adapted for use with a corresponding sending and receivingantenna in the pump assembly (e.g., antenna 1002 in FIG. 51), and a userinterface 1010. Operations may be controlled by a controller 1012 (e.g.a microprocessor, memory, firmware and/or software). Communicationbetween the pump assembly 200 and remote control 1000 may be in the formof RF based communication (as described above) or other communicationmediums such as infrared and magnetic. The user interface 1010 mayinclude a visual display 1014 (e.g., an LCD display) and a plurality ofbuttons 1016 (e.g., switches, membrane keys, etc.). An alarm device1018, which may be audible (e.g., a buzzer), palpable (e.g., avibrator), visible (e.g., an LED), or any combination thereof, may alsobe provided.

The exemplary remote control 1000 may also include a port or connector1020 (e.g., a USB connector) that allows communication with, forexample, a personal computer, a printer, or a clinician's programmer.

The exemplary remote control 1000 may also be provided with a proximitysensor 1022 that, when active, senses the distance between the remotecontrol and the pump assembly 200. The controller 1012 may actuate thealarm device 1018 if the distance is too great, in order to remind theuser to keep the remote control 1000 close at hand.

The exemplary remote control 1000 may be configured to facilitate one,some or all of the following operations: (1) turning the remote control1000 on or off, (2) associating (or “assigning”) the remote control 1000to the pump assembly 200, (3) obtaining status information such asbattery charge level, medicament level, and/or alarm conditions, (4)silencing the pump assembly alarm, (5) selecting options that may beassociated with the pump assembly alarm such as type of alarm (audible,palpable, and/or visible) and strength/volume of alarm, (6) connectingthe remote control to a computer to, for example, update remote controlor pump assembly firmware, load and delete delivery profiles stored inthe pump assembly or remote control, and otherwise re-program the pumpassembly or remote control, and (7) selecting medicament options such asmedicament concentrations.

Other operations that may be performed through operation of the remotecontrol 1000 include (1) selecting and initiating a stored medicamentdelivery profile, (2) increasing and decreasing medicament dose rate,(3) retracting the plunger pusher from the cartridge to the homeposition, and/or (4) pausing a dispensing operation. A user may pausedelivery in order to remove or replace a patient applied structure (e.g.a cartridge, cannula or baseplate), adjust for a current or anticipatedchange body condition (e.g., low glucose, vigorous exercise), follow aphysician's suggestion, or disconnect the pump assembly from the bodyfor any other reason.

The exemplary remote control 1000 may be configured to generate anindicator, based on information from the pump assembly controller (e.g.,controller 240), that is indicative of the amount of time remaining inthe current dispensing program and/or the amount of time until the nextcartridge replacement and/or the amount of time until the pump assemblybattery requires recharging. The indicator may be audible, visible,palpable or combinations thereof. A time remaining indicator, such asthe exemplary time indicator 1024 on the remote control visual display1014 (FIG. 98), may be useful for a variety of reasons. For example,knowledge of the time remaining prior to next cartridge replacementand/or battery recharging allows the patient to determine, based atleast in part on the current time of day and upcoming events (e.g.,travel or sleep), whether or not it would be more convenient to replacethe medicament cartridge at a time prior to the end of the dispensingprogram and/or recharge the battery prior to the point at which it isnecessary.

One exemplary type of visible time remaining indicator is the pie chartstyle “hours left” gauges 1024 and 1025 illustrated in FIG. 98. Anyother suitable visible indicator may be employed. The visible indicators1024 and/or 1025 may be displayed whenever the display 1014 is active,displayed in response to a user inquiry, displayed intermittently,and/or displayed in response to predetermined event (e.g., when 8 hoursare remaining).

The exemplary remote control 1000 may be configured to generate anindicator, based on information from the pump assembly controller, thatis indicative of the amount of medicament remaining in the cartridge.The indicator may be audible, visible, palpable, or combinationsthereof. The exemplary visible “volume remaining” indicator 1026 may bedisplayed whenever the display 1014 is active, displayed in response toa user inquiry, displayed intermittently, and/or displayed in responseto predetermined event (e.g. 25% remaining).

Remaining time calculations may be performed by the pump assemblycontroller 240 and be based, for example, on the total delivery durationfor the associated cartridge (in view of the delivery program andcartridge volume) and the portion of that total delivery duration whichhas thus far passed based on actual delivery time (i.e., taking intoaccount user stoppages, if any). Alternatively, or in addition, thecalculations may be based on the initial volume of the associatedcartridge, the total number of motor revolutions necessary to completelydeliver the initial volume, the number of motor revolutions that haveoccurred prior to the calculation (as evidenced by, for example, encodersignals), and amount of time, based on the delivery program, before thetotal number of revolutions will be reached. Remaining volume (asopposed to remaining time) calculations performed by the controller 240may be based on the initial volume of the associated cartridge, thenumber of motor revolutions necessary to completely deliver the initialvolume, and the number of motor revolutions that have occurred prior tothe calculation (as evidenced by, for example, encoder signals). Here,the information received by the remote control 1000 from the pumpassembly controller 240 will be the actual time/volume information to bedisplayed.

It should also be noted that the calculations described above may beperformed by the remote control controller 1012. Here, the informationreceived by the remote control 1000 from the pump assembly controller240 may simply be encoder information. All other information (e.g. starttime, program being implemented, etc.) would be already available at theremote control itself.

Additionally, in lieu of actual calculations, the pump assemblycontroller 240 and/or the remote control controller 1012 may bepre-programmed to automatically generate a time and/or volume indicatorbased on encoder information and a pre-programmed look-up tableassociated with the dispensing program.

With respect to the amount of time until the battery 238 requiresrecharging, the pump assembly may be provided with a battery managementchip (or other suitable battery management apparatus) that determineswhen recharging is necessary. For example, recharging may be necessarywhen the battery voltage is reduced from the fully charged voltage to apredetermined voltage that is less than the fully charged voltage. Theamount of time remaining may be estimated by the battery managementapparatus based on factors such as battery age, battery temperature, andthe dispensing program. The battery management apparatus may be part of,or operably connected to, the pump assembly controller 240. Thecontroller 240 is configured to generate a signal indicative of theamount of time remaining until the battery will require recharging.

One exemplary method that may stem from use of the information providedby a pump assembly and/or a remote control is as follows. The userlearns from the remote control (e.g., remote control 1000) the amount oftime (or medicament) remaining in the medicament dispensing programrunning on the associated infusion device (e.g., cartridge 100 and pumpassembly 200). The information may be provided by the remote control1000 in audible, visible and/or palpable form (e.g., with the timeindicator 1024 and/or the volume remaining indicator 1026). The patientthen determines, based on anticipated activity or activities, whether itwould be preferable to remove a not yet empty medicament cartridge andreplace it with a new medicament cartridge immediately, in the nearfuture, or after the dispensing program has been completed and thecartridge is empty. It may be that, at the end of the remaining time,the user anticipates activity (e.g., sleeping, traveling, exercising,attending a social or business event) which would render cartridgereplacement inconvenient or impossible. Thus, the user may decide thatit is better to replace the cartridge before it is empty, and then doso.

Turning to FIG. 100, the exemplary remote control 1000 may be used toalert the user to, and specifically identify, a variety of alarm causes(or “conditions”). The exemplary remote control 1000 may be used tosuggest actions to be taken in response to the alarms. The alarm causesand suggested actions may be provided in audible or visible form.Exemplary alarm causes are identified AC1-AC16 in FIG. 100, and arefollowed by a suggest action. “R and R” is used in FIG. 100 to represent“remove and replace,” and references to “cannula/baseplate” arereferences to both “patch pump” style baseplates (e.g., baseplate 500),which are used in conjunction with a separate cannula, and “pocket pump”style baseplates (e.g., baseplate 501), which may have their own cannulaas part of an attached infusion set.

The exemplary alarm cause (or “conditions”) may include some or all of,but are not limited to, a pump assembly 100 (and/or a baseplate 500)falling off the user's skin (AC-1), a battery with a low charge level(AC-2), an error associated with an acoustic transducer or other alarm(AC-3), a fully depleted battery (AC-4), a battery fault (AC-5), anocclusion (AC-6), a telemetry fault (AC-7), a motor error, such motorcurrent too low (AC-8), a baseplate/pump assembly disconnection (AC-9),a firmware checksum error (AC-10), a variables checksum error (AC-11), alow reservoir (AC-12), an empty reservoir (AC-13), a battery fault(AC-14), a zeroing procedure error (AC-15), and a temperature (e.g.within the housing 202) above a preset limit (AC-16). Other alarmconditions may include an error associated with pressure sensinghardware and delivery decision hardware.

Although the inventions disclosed herein have been described in terms ofthe preferred embodiments above, numerous modifications and/or additionsto the above-described preferred embodiments would be readily apparentto one skilled in the art. It is intended that the scope of the presentinventions extend to all such modifications and/or additions and thatthe scope of the present inventions is limited solely by the claims setforth below.

Finally, with respect to terminology that may be used herein, whether inthe description or the claims, the following should be noted. The terms“comprising,” “including,” “carrying,” “having,” “containing,”“involving,” and the like are open-ended and mean “including but notlimited to.” Ordinal terms such as “first”, “second”, “third” in theclaims do not, in and of themselves, connote any priority, precedence,or order of one claim element over another or temporal order in whichsteps of a method are performed. Instead, such terms are merely labelsto distinguish one claim element having a certain name from anotherelement having a same name (but for the ordinal term) to distinguish theclaim elements. “And/or” means that the listed items are alternatives,but the alternatives also include any combination of the listed items.The terms “approximately,” “about,” “substantially” and “generally”allow for a certain amount of variation from any exact dimensions,measurements, and arrangements, and should be understood within thecontext of the description and operation of the invention as disclosedherein. Terms such as “top,” “bottom,” “above,” and “below” are terms ofconvenience that denote the spatial relationships of parts relative toeach other rather than to any specific spatial or gravitationalorientation. Thus, the terms are intended to encompass an assembly ofcomponent parts regardless of whether the assembly is oriented in theparticular orientation shown in the drawings and described in thespecification, upside down from that orientation, or any otherrotational variation therefrom.

We claim:
 1. An infusion pump assembly for use with a medicamentcartridge including a reservoir and a plunger, the assembly comprising:a housing having a medicament cartridge receiving area; a plunger pusherhaving a home position and movable in and out of the cartridge receivingarea; a drive mechanism, including a motor, that drives the plungerpusher; and a controller that automatically causes the motor to withdrawthe plunger pusher out of a medicament cartridge in the cartridgereceiving area and return the plunger pusher to the home position both(a) after receiving a signal from an encoder indicating that apredetermined number of rotation counts of the motor, which indicatethat the reservoir is empty, has occurred and (b) when the medicamentcartridge is properly positioned within the cartridge receiving area andthere is a lack of encoder signals during a medicament deliveryoperation.
 2. An infusion pump assembly as claimed in claim 1, whereinthe encoder indicates that the motor is not turning when the plungerpusher is stalled or when a structure of the plunger pusher is blockingrotation of a portion of the drive mechanism.
 3. An infusion pumpassembly as claimed in claim 1, wherein the drive mechanism includes aplanetary gearbox and a transverse gear train operatively between themotor and a lead screw that drives the plunger pusher.
 4. An infusionpump assembly as claimed in claim 3, wherein the drive mechanismincludes a nut that operatively connects the plunger pusher to the leadscrew; the plunger pusher has structure that prevents rotation of theplunger pusher with the lead screw; and the nut is molded with theplunger pusher or pressed into the structure.
 5. An infusion pumpassembly as claimed in claim 1, further comprising: a slidable latch,associated with the housing, and movable between a first position thatdoes not prevent the medicament cartridge from being inserted into andremoved from the cartridge receiving area and a second position, when atleast a portion of the pusher is in the cartridge receiving area, thatprevents removal of the medicament cartridge from the cartridgereceiving area.
 6. An infusion pump assembly as claimed in claim 5,wherein the slidable latch includes a bias mechanism that biases theslidable latch to the second position when the at least a portion of thepusher is in the medicament cartridge.
 7. An infusion pump assembly asclaimed in claim 6, wherein the housing has an interior abutment wallmounted therein and the bias mechanism biases the slidable latch towardthe abutment wall such that a medicament cartridge in the cartridgereceiving area will be pushed against the abutment wall.
 8. An infusionpump assembly as claimed in claim 6, wherein the slidable latch includesa latch recess and a locking member, and the locking member is disposedin the latch recess when the portion of the pusher is in the cartridgereceiving area.
 9. An infusion pump assembly as claimed in claim 1,wherein the housing has a top surface opening aligned with at least aportion of the cartridge receiving area.
 10. An infusion pump assemblyas claimed in claim 1, wherein the plunger pusher is movable to a homeposition outside the cartridge receiving area; and the infusion pumpassembly further comprises a switch located relative to the plungerpusher such that the switch is actuated when the plunger pusher isretracted, from a position where at least a portion of the plungerpusher is within the cartridge receiving area, to the home position. 11.An infusion pump assembly as claimed in claim 1, wherein the housingincludes a cartridge compartment that defines the medicament cartridgereceiving area; the plunger has a home position; and the medicamentcartridge can be inserted into and removed from the cartridgecompartment in a direction generally perpendicular to the longitudinalaxis of the plunger pusher when the plunger is in the home position. 12.An infusion pump assembly as claimed in claim 1, wherein the plungerpusher moves along a pusher axis; and the infusion pump assembly furthercomprises a latch assembly that blocks removal of the medicamentcartridge from the housing in a direction orthogonal to the pusher axiswhen at least a portion of the plunger pusher is within the cartridge.13. An infusion pump assembly as claimed in claim 12, wherein the latchassembly includes a latch component that is in a cartridge removalblocking position when at least a portion of the plunger pusher iswithin the cartridge and is biased to an unblocking position when noportion of the plunger pusher is within the cartridge.
 14. An infusionpump assembly as claimed in claim 1, wherein the controller controls theplunger pusher to drive the plunger of a cartridge that is locatedwithin the cartridge receiving area during the medicament deliveryoperation.
 15. An infusion pump assembly for use with a medicamentcartridge including a reservoir and a plunger, the assembly comprising:a housing having a medicament cartridge receiving area; a plunger pushermovable in and out of the cartridge receiving area; a drive mechanism,including a motor, that drives the plunger pusher; a controller thatautomatically causes the motor to withdraw the plunger pusher out of thecartridge receiving area (a) after receiving a signal from the encoderindicating that a predetermined number of rotation counts of the motor,which indicate that the reservoir is empty, has occurred or (b) whenthere is a lack of encoder signals; and a slidable latch, associatedwith the housing, and movable between a first position that does notprevent the medicament cartridge from being inserted into and removedfrom the cartridge receiving area and a second position, when at least aportion of the pusher is in the cartridge receiving area, that preventsremoval of the medicament cartridge from the cartridge receiving area,the slidable latch including a body member; a pair of first and secondspaced legs extending from the body member and spaced from and parallelto one another and in the same plane, the first leg having a firstthrough-hole, the second leg having a second through-hole; a first rodthrough the first through-hole; a first coil spring around the first rodand biased against the first leg; and a second coil spring around thesecond rod and biased against the second leg.
 16. An infusion pumpapparatus for use with a medicament cartridge including a reservoir anda plunger, the assembly comprising: a housing having a medicamentcartridge receiving area; a plunger pusher that moves along a pusheraxis in and out of the cartridge receiving area; a drive mechanism,including a motor, that drives the plunger pusher; a controller thatautomatically causes the motor to withdraw the plunger pusher out of thecartridge receiving area (a) after receiving a signal from the encoderindicating that a predetermined number of rotation counts of the motor,which indicate that the reservoir is empty, has occurred or (b) whenthere is a lack of encoder signals; and a latch assembly that blocksremoval of the medicament cartridge from the housing in a directionorthogonal to the pusher axis when at least a portion of the plungerpusher is within the cartridge, the latch assembly including a latchcomponent that is in a cartridge removal blocking position when at leasta portion of the plunger pusher is within the cartridge and a springthat biases the latch component to the unblocking position when noportion of the plunger pusher is within the cartridge.
 17. An infusionpump apparatus for use with a medicament cartridge including a reservoirand a plunger, the assembly comprising: a housing having a medicamentcartridge receiving area; a plunger pusher that moves along a pusheraxis in and out of the cartridge receiving area; a drive mechanism,including a motor, that drives the plunger pusher; a controller thatautomatically causes the motor to withdraw the plunger pusher out of thecartridge receiving area (a) after receiving a signal from the encoderindicating that a predetermined number of rotation counts of the motor,which indicate that the reservoir is empty, has occurred or (b) whenthere is a lack of encoder signals; and a latch assembly that blocksremoval of the medicament cartridge from the housing in a directionorthogonal to the pusher axis when at least a portion of the plungerpusher is within the cartridge, the latch assembly including a latchcomponent that is in a cartridge removal blocking position when at leasta portion of the plunger pusher is within the cartridge and is biased toan unblocking position when no portion of the plunger pusher is withinthe cartridge and a sliding latch tensioner that slides relative to thelongitudinal axis of the plunger pusher and pushes against the latchcomponent to move the latch component to the blocking position.